Downstaging Rate Research Articles

P-265 Neoadjuvant radiotherapy for locally advanced rectal cancer during the first wave of COVID19 pandemic: Guy’s cancer cohort experience

The Covid-19 pandemic is a healthcare emergency with a significant impact on cancer services provision. In March 2020, our institution adopted the ESMO expert consensus guidelines for radiotherapy management of rectal cancer during the pandemic. Here we present short-term oncological outcomes of this approach compared to the same period in 2018. Patients who underwent neoadjuvant (chemo) radiotherapy for rectal cancer between 1st March 2020 and 31 May 2020 were identified from a research ethics committee (REC)-approved research database for cancer patients (Guy’s Cancer Cohort). Patient demographics and treatment characteristics were extracted and compared with a control cohort treated in the same period in 2018. The definition of local response was based on identification of downstaging on re-staging Magnetic Resonance Imaging (MRI) post neoadjuvant treatment (mrT3c/d-4 to mrT0-2 and mrT2 to mrT0-1) and classified in a binary format (response vs no response). In addition, in patients who underwent total mesorectal excision (TME), neoadjuvant rectal (NAR) score was calculated, as described previously, and classified into low (<8), intermediate (>=8<=16) and high (>16). The frequency of MRI and pathological response was compared using non-parametric Fisher exact test. Thirty patients were treated in the three-month period in 2020 as compared with 21 in 2018 (43% increase). No statistically significant differences were observed in baseline tumour characteristics. The use of neoadjuvant short-course radiotherapy (SCRT) treatment increased significantly from 19% of cases in 2018 to 50% during the pandemic, which was reflected in reduced radiotherapy-related hospital footfall (median 15 appointments in 2020 vs 25 appointments in 2018). While the use of concomitant fluoropyrimidines was lower (47 vs 71%), the use of induction chemotherapy was higher (30 vs 19%) in 2020 compared to 2018, which may reflect more prevalent use of total neoadjuvant treatment. There was no difference in the proportion of MRI responders between cohorts (52% in 2020 vs 38% in 2018). In patients who underwent TME, there was no difference in the proportion of R1 resection (0 in 2020 vs 9% in 2018), median NAR scores (8 (1-30) in 2020 v 15 (range 4-50) in 2018) or NAR score categories (22% good responders, 64% intermediate and 14% non-responders during Covid-19 vs 9% good responders, 55% intermediate and 36% non-responders in 2018). Changes in radiotherapy treatment of rectal cancer during Covid-19 pandemic, including more frequent use of SCRT (often in combination with neoadjuvant chemotherapy), did not seem to have negatively impacted short-term oncological outcomes, as measured by MRI downstaging rates and NAR scores following TME. The effect of the pandemic on medium and long-term oncological outcomes is still awaited.

Mucinous Adenocarcinoma Predicts Poor Response and Prognosis in Patients With Locally Advanced Rectal Cancer: A Pooled Analysis of Individual Participant Data From 3 Prospective Studies

PurposeTo evaluate the predictive implications and prognosis of mucinous adenocarcinoma (MAC) in locally advanced rectal cancer (LARC) with intensified neoadjuvant treatment. MethodsIndividual patient data of LARC patients from 3 prospective clinical trials was analyzed. Neoadjuvant treatment regimens comprised chemoradiotherapy (CRT) with fluorouracil (5-FU) or mFOLFOX6, neoadjuvant chemotherapy alone with mFOLFOX6 or mFOLFOXIRI. The postoperative pathological result, local recurrence and disease-free survival (DFS) were retrospectively analyzed in patients with MAC and adenocarcinoma (AC) with neoadjuvant treatment. ResultsTotally, 743 patients were recruited, with 620 patients eligible for analysis. Fifty-three (8.5%) patients were MAC. The pathological complete response (pCR) rate and tumor downstaging rate (ypStage 0-I) between MAC and AC patients was 7.5% vs. 22.0% (P = .01) and 20.8% vs. 48.7% (P < .001), respectively. Among patients receiving preoperative CRT with 5FU or mFOLFOX6, the pCR rate and tumor downstaging rate between MAC and AC patients was 11.1% vs. 27.3% (P = .03) and 23.7% vs. 52.6% (P = .001), respectively. Regarding neoadjuvant chemotherapy alone with mFOLFOX6 or mFOLFOXIRI, the pCR rate and tumor downstaging rate was 0 vs.13.2% (P = .11) and 11.8% vs. 42.5% (P = .03) between MAC and AC group, respectively. With the median follow-up time of 38.9 months, the 3-year DFS and 3-year locoregional recurrence rate was 58.4% vs. 77.6% (P = .02) and 26.0% vs. 5.7% (P = .001) in the MAC and AC group, respectively. MAC (hazard ratio [HR] 1.85, 95% confidence interval [CI], 1.15-2.98), PNI (HR 3.23, 95% CI, 1.85-5.72) and LVI (HR 2.04, 95% CI, 1.02-4.08) were independent prognosis factors and were associated with worse DFS. ConclusionsPatients with MAC of the rectum are associated with a lower pCR rate and tumor downstaging rate, higher incidence of local recurrence, and poorer DFS with neoadjuvant treatment.

CCTG CO.28 primary endpoint analysis: Neoadjuvant chemotherapy, excision and observation for early rectal cancer, the NEO trial.

3508 Background: CO.28 (NCT03259035) is a phase II study designed to determine if patients with cT1-T3a/bN0 rectal cancer can be treated with induction chemotherapy (FOLFOX/CAPOX) and organ-preserving surgery. Methods: Patients with MRI staged cT1-3a/bN0 tumors and no pathologic (p) high risk features received 6/4 cycles of FOLFOX/CAPOX, repeat sigmoidoscopy/pelvic MRI and subsequent Transanal Endoscopic Surgery (TES) in the absence of tumor progression. ypT0/T1N0 tumors were treated with observation while ypT2+ or ypN+ stage were recommended Total Mesorectal Excision (TME). The primary endpoint was protocol specified Organ Preservation Rate (psOPR = ypT0/T1N0, no p high risk features) and actual Organ Preservation Rate (aOPR = ypT0/T1N0 stage plus higher yp stage patients who declined TME surgery). The study would be considered negative with an psOPR of 50% or lower (H0) and as promising if it is 65% or higher (H1). Results: Between 08/2017 to 05/2020, 58 eligible patients were accrued in Canada and the United States, median age was 67 years, 71% male. All had well-moderately differentiated, non-mucinous rectal adenocarcinoma and median tumor height was 6 cm (range 0-18). Median follow-up was 15.4 months. Chemotherapy with FOLFOX (32) or CAPOX (26) was administered, 90% completed all planned cycles. A total of 56/58 (97%) proceeded to TES, while one patient was ineligible due to tumor progression (1.7%) and one declined. In the intention to treat analysis, the psOPR was 57% (95% CI 43-70%) while the aOPR was 79% (95% CI 67% to 89%) due to 13/23 declining recommended TME surgery. Of 10 patients who proceeded to recommended TME, a complete R0 TME was performed in 9/10, and no p residual carcinoma was found in 7/10. Crude loco-regional (LR) and distant recurrence rates were 3.5% (95% CI 0.4 to 12%) and 0%, respectively. A recurrence occurred in 1/13 patients who initially declined TME surgery. Conclusions: In select patients with early stage rectal cancer, three months of induction CAPOX/FOLFOX followed by TES resulted in a high OPR without the use of pelvic irradiation. The observed high rate of pathologic downstaging may point to high chemo-responsiveness in early rectal adenocarcinoma with no p high risk features. Further trials to evaluate this approach are justified and updated results will be presented. Clinical trial information: NCT03259035. [Table: see text]

Updated results of phase II trial using escalating doses of neoadjuvant atezolizumab for cisplatin-ineligible patients with nonmetastatic urothelial cancer (NCT02451423).

e16510 Background: Patients (pts) with muscle-invasive bladder cancer (MIBC) ineligible for cisplatin-based chemotherapy have no standard systemic therapy options and are prioritized for radical cystectomy (RC) alone. This prospective clinical trial investigated the safety and efficacy of escalating doses of neoadjuvant atezolizumab (N-ATZ) prior to RC in MIBC pts. Methods: This is a single-institution, phase II trial of escalating doses of N-ATZ (1200 mg IV every 3 weeks) in pts with MIBC. Key inclusion criteria were resectable urothelial carcinoma of the bladder (T2-T4a,N0-1,M0) and inability to receive cisplatin-based treatment (eGFR &lt; 60 mL/min, G≥2 neuropathy/hearing loss, pt decision). Pts with high-risk disease at RC were eligible to receive adjuvant ATZ for up to 16 total doses. Pts were followed for up to 2 years following RC. Primary efficacy endpoint was pathologic complete response (pCR; pT0N0). Secondary endpoints were safety of treatment, rate of pathologic downstaging (≤pT1N0), response based on PD-L1 status, and overall survival (OS) and recurrence-free survival (RFS) at 1 and 2 years from RC. Results: A total of 20 pts were enrolled and sequentially treated with one (n=6), two (n=5), and three (n=9) cycles of N-ATZ prior to RC. Median age was 69 (range 61-81), 75% were male and 85% Caucasian. Pts were cisplatin-ineligible due to low GFR (35%), hearing loss (25%) or neuropathy (10%); the rest refused cisplatin (30%). Most pts had pT2 disease (80%); the remainder, pT3/pT4 (15%/5%), and 10% had cN1. Among 17 pts with available tumor PD-L1 status, 76% had PD-L1 positive (CPS≥10) tumors. pCR was observed in 2 pts (10%) with 1 and 2 ATZ doses, whereas pathologic downstaging was observed in 5 pts (25%) across all 3 doses (Table). All pts completed intended treatment and RC within the trial-defined timeframe. Perioperative TRAEs of any grade occurred in 75%, but only 10% had G3 TRAEs (diarrhea, fecal incontinence). There were no G4/G5 events. Median follow-up from RC was 23.6 months and 75% were still followed at the time of data cutoff in 2/2021. Among evaluable pts, 1-year RFS and OS were 72% and 94% while 2-year RFS and OS were 64% and 69%. PD-L1 positive pts had superior OS (logrank p=0.06) and RFS (p=0.10) relative to PD-L1 negative pts. Conclusions: N-ATZ was well tolerated at all three dose levels and did not delay or prevent surgery. As few as 1 to 2 ATZ doses resulted in pathologic downstaging, including pCR. Although pCR rate in this trial was lower than expected, most pts had a durable recurrence-free period and all evaluable pts with tumor downstaging were alive and recurrence-free at 2 years following RC. Increased tumor PD-L1 expression was suggestive of improved outcomes and further biomarker analyses are ongoing. Clinical trial information: NCT02451423. [Table: see text]

A phase 2 study of cabozantinib in combination with atezolizumab as neoadjuvant treatment for muscle-invasive bladder cancer (HCRN GU18-343) ABATE study.

TPS4591 Background: ABACUS and PURE-01 trials demonstrated the activity of single agent atezolizumab and pembrolizumab respectively as neoadjuvant therapy for muscle invasive urothelial carcinoma (MIUC). However, downstaging to non-muscle invasive disease was noted in only 50 percent of patients. Resistance to programmed death (PD)- 1/L-1 antibodies is likely to include factors such as impaired dendritic cell maturation/function, infiltration of T-Regs and myeloid derived suppressor cells, impaired T-cell priming and T-cell trafficking in tumors. Cabozantinib is a tyrosine kinase inhibitor which targets MET, AXL, MER, Tyro3 and VEGFR2. Cabozantinib has a unique immunomodulatory profile and has demonstrated clinical activity as monotherapy and in combination with PD-1/L1 antibodies in various solid tumors including UC, renal cell cancer, castrate- resistant prostate cancer, and non-small cell lung cancer. We hypothesize that the combination of cabozantinib and atezolizumab as neoadjuvant therapy for MIUC would improve rates of pathologic downstaging compared to single-agent checkpoint inhibitors. Methods: ABATE(NCT04289779) is an open-label, single arm, multi-center study to assess the efficacy and safety of cabozantinib with atezolizumab as neoadjuvant therapy for cT2-T4aN0/xM0 MIUC. An estimated 38 patients will be enrolled and receive cabozantinib 40 mg PO daily with atezolizumab 1200mg every 3 weeks for a total duration of 9 weeks followed by radical cystectomy. Adults (≥18 years) with resectable UC who are either cisplatin-ineligible or decline cisplatin are eligible. Patients are required to have an ECOG PS of 0-2 and provide tumor tissue for PD-L1 analysis. UC should be predominant component (≥ 50%). Previous systemic anticancer therapies for MIUC are not permitted. CT/MRI will be performed before investigational therapy and cystectomy. Primary endpoint is pathologic response rate defined as the absence of residual muscle-invasive cancer in the surgical specimen ( &lt; pT2). Secondary endpoints are safety and toxicity, pathologic complete response rate and event-free survival. Exploratory end points include patient-reported outcomes and outcome associations with biomarkers. Accrual began May 2020. Clinical trial information: NCT04289779.

Retrospective cohort of total neoadjuvant therapy (TNT) in high-risk locally advanced rectal cancer (HR-LARC): Additional sintilimab (PD-1) in tri-modality approach.

e15604 Background: TNT is an emerging practice adapted to ensure all patients (pts) receive of systemic therapy, particularly for pts with high risk recurrence. Our previous phase II trial of TNT in MRI stratified HR-LARC demonstrated high down-staging rate and improved complete response with acceptable toxicity (manuscript under review). The aim of this retrospective cohort study was to evaluate the feasibility of sintilimab in combination with chemotherapy in TNT tri-modality treatment of pts with HR-LARC. Methods: HR-LARC pts who were given 3 cycles of sintilimab (200mg, iv, q3w) in combination with CapeOx followed by sequential long-course radiotherapy (IMRT GTV50.6 Gy/CTV 41.8 Gy/22f), 2 cycles CapeOx and surgery were enrolled from Beijing Cancer Hospital, CHN. The high risk was defined as middle to low RC (≤8cm to ARJ or 12 cm per sigmoidoscopy) with ≥1 factor from MRI features: clinical stage T3c/d-T4a/b, or N2 or MRF (+) or EMVI (+). The clinical outcomes included pathological response, major response rate (cCR+MPR), R0 resection rate, and toxicity. Results: From Feb 2019 to Oct 2020, 19 cases were identified with median distal location 4 cm (3-7), T2/T3/T4 1/15/3, N1/N2a/N2b 7/4/8, MRF+ 8/11, EMVI+ 8/11. Other characteristics were pMMR/MSS 100%, age 67y (47-78), male 57.9%, PS 1 100%, c-stage III 100% (18), median diameter of primary lesion 5.1 cm (2.1-7.5). As of 30th Dec 2020, 84.2% (16/19) received neoadjuvant therapy and completed surgical resection, with R0 resection rate 100%. One pts denied surgery and two chose watch &amp; wait since achieving cCR 10.5% (2/19). Of 16 resection pts, 13 had sphincter-sparing surgery (LAR or TaTME). One had Hartmann procedure, and two had abdominal perineal resection. The sphincter preservation rate was 84.2% (16/19). The pCR was 26.3% (5/19), and MPR was 47.3% (9/13). The major response rate was 57.9% (11/19), 4/2/13 of which completed intact TNT schema, induction and RT, and induction phase only, respectively. Treatment related adverse events (TRAE) occurred in 6 pts (31.6%) in grade (gr) 1-2 (CTCAE 5.0) without any gr 3-5 events occurred. Immune-related AEs were found in 2 pts with hypothyroidism (gr 1,2). Postoperative complications included two gr2 (Clavien-Dindo) events of anastomtic bleeding and infection. Of note, 3 pts with anastomotic stenosis got stoma reversion after dilation. Conclusions: Given the impressive response rate (57.9%), this retrospective analysis suggested a potential enhanced anti-cancer activity and good tolerability in pMMR/MSS HR-LARC from sintilimab in combination with TNT. The encouraging results warrant further evaluation of this approach in prospective trial.

Osimertinib as neoadjuvant treatment for resectable stage II-IIIB EGFR mutant lung adenocarcinoma (NEOS).

8524 Background: Neoadjuvant treatment has demonstrated efficacy in several types of cancer and is increasingly used for the treatment of early-stage cancers with the potential of cancer downstaging to enhance complete surgical resection and to improve clinical outcomes. Recent evidences have demonstrated that the neoadjuvant use of first/second-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) may provide clinically meaningful improvement in EGFRm non-small cell lung cancer (NSCLC) patients, however, limited data were reported on osimertinib, the third-generation EGFR-TKI, in the neoadjuvant setting. Here we present an interim analysis of osimertinib as neoadjuvant treatment for resectable EGFRm NSCLC. Methods: NEOS is a prospective, multi-center, single-arm study to evaluate the efficacy and safety of osimertinib as neoadjuvant treatment in resectable EGFRm (19del/L858R) lung adenocarcinoma. Eligible patients were treated with osimertinib 80 mg orally per day for six weeks followed by surgery. Assessment of response to neoadjuvant therapy was performed according to RECIST 1.1. The primary endpoint was response rate. Secondary endpoints included safety, R0 surgical resection rate, quality of life, major pathologic response (MPR) rate, pathological complete response (pCR) rate, and N2 downstaging rate. Results: As of Dec. 17, 2020, 18 eligible patients (median age 61 [range 46-73], 27.8% male, 22.2% ECOG PS 1) have been enrolled. Patients with clinical stages IIa, IIb, and IIIa (8th AJCC) accounted for 16.7%, 22.2% and 61.1%, respectively. Half (9/18) of the patients had EGFR exon 21 L858R mutations and the other half (9/18) had EGFR exon 19del mutations. Amongst all 15 patients who completed efficacy assessment after neoadjuvant osimertinib, the response rate (RR) was 73.3% (11/15) and the disease control rate (DCR) was 100% (15/15). R0 surgical resection was performed in 93.3% (14/15) patients. Pathological downstaging occurred in 53.3% (8/15) patients. 42.9% (3/7) of the patients with confirmed N2 lymph nodes experienced downstaging to N0 disease after receiving neoadjuvant osimertinib. One patient was identified with a pCR. Adverse events (AEs) were reported in 66.7% (12/18) of patients, with the most common AE being rash (8/18, 44.4%), oral ulceration (8/18, 44.4%), and diarrhea (5/18, 27.8%). No grade 3-5 AEs or serious AEs were reported. Conclusions: Interim analysis from this study indicated neoadjuvant osimertinib as an effective and feasible treatment in patients with resectable stage II-IIIB EGFRm NSCLC. The trial is ongoing and the final results will be provided in the future. Clinical trial information: ChiCTR1800016948.

The very early tumor regression rate and safety of anlotinib combined with sintilimab and chemotherapy for advanced non-small cell lung cancer without driver mutations.

e21090 Background: Unlike bevacizumab, anlotinib, which is also an anti-angiogenic drug, is indicated for lung squamous cell carcinoma(LSCC). A phase IB study showed that the first-line therapy with anlotinib and sintilimab for stage IIIB to IV NSCLC with negative driver genes has the objective response rate of 72.7%. Regardless of the PD-1 expression level, this combination method has consistent therapeutic benefit. According to the IMpower150 study, the four-drug combination therapy has a synergistic effect and prolong the survival time. It is necessary to further explore the efficacy and safety of anlotinib combined with sintilimab and chemotherapy for NSCLC without driver mutations. Methods: We retrospectively analyzed the patients of newly diagnosed unresectable stage IIIA-IVB NSCLC who received platinum-containing dual-drug chemotherapy combined with anlotinib and sintilimab in our hospital from January 2019 to December 2020. Patients receive at least one cycle of treatment, and the efficacy can be evaluated. The main observation indicators are the very early tumor regression rate and the safety. Results: This study included 11 patients with stage IIIA-IVB NSCLC with no driver mutations that were not resectable. Ten patients (90.9%) were male, with a median age of 65 years. The pathological types were LSCC (7, 63.6%), lung adenocarcinoma (3, 27.3%), and poor differentiated carcinoma (1, 9.1%). Six patients were with stage ⅢA-ⅢB, 4 patient with ⅢC-IVB. Eleven patients received an average of 1.63 cycles of treatment. In order to evaluate the efficacy of multi-drug combination therapy in a timely manner, and effectively avoid the risk of hemoptysis caused by anlotinib-induced pulmonary cavity, all patients were evaluated for efficacy after receiving one cycle of treatment. Eight patients achieved very early tumor regression (defined as tumor shrinkage ≥30% after receiving one cycle of treatment in the evaluation of efficacy), 2 patients achieved stable disease, and 1 patients achieved disease progression. The very early tumor regression rate was 72.7%. Three patients with locally advanced (ⅢA-ⅢB) NSCLC underwent radical R0 resection and the downstage rate reached 100%; 2 patients underwent radical radiotherapy. At the last follow-up time in February 2021, one patient died, the remaining patients were alive. No treatment-related grade 3-4 adverse reactions were observed. Conclusions: The high rate of very early tumor regressions in inoperable locally advanced NSCLC provided opportunities for radical surgery and radiotherapy in a short period of time. And the safety is satisfactory. Therefore, our research group has registered the prospective study of anlotinib combined with sintilimab and chemotherapy for the neoadjuvant downstage treatment of stage III NSCLC (Registration number: ChiCTR1900026631).

A prospective, phase II, single-arm study of neoadjuvant/conversion therapy with camrelizumab, apatinib, S-1 ± oxaliplatin for locally advanced cT4a/bN+ gastric cancer.

4061 Background: The prognosis of cT4a/bN+ gastric cancer (GC) is poor due to low R0 resection rate and frequent recurrence. We evaluated the feasibility, safety, and efficacy of a combination of immunotherapy, anti-angiogenesis, and chemotherapy for neoadjuvant/conversion treatment of cT4a/bN+ GC. Methods: Patients with T4a/bN+ GC were enrolled to receive camrelizumab (200mg d1), apatinib (250mg d1-14), S-1 (50mg bid d1-10) ± oxaliplatin (85 mg/m2 d1) for at least 2 cycles, followed by re-evaluation and operation. Peri-treatment samples were collected for whole-exome, transcriptome, and T cell receptor (TCR) sequencing. Pathological response (PR) and its relationship with genomic biomarkers are primary endpoints. Results: 25 patients were enrolled, with median age 63 (48-70), 19 male, 11 cT4aN2-3 and 14 cT4bN2-3. The radiological response (RR) rate of the treatments was 33.3% (8/24), and tumor down-staging rate 79.2% (19/24). 24 patients completed re-evaluation, with 3 failed conversion, 2 refused surgery, and 1 postponed surgery for immune-related pneumonia. Among the 18 patients with R0 resection, 3 got complete PR (CPR), 2 major PR (MPR, ≤10% residual cancer cells), and 3 partial PR (11̃49% residual cancer cells), with a PR rate of 44.4% and MPR+ (MPR &amp; CPR) rate of 27.8%. 62.5% patients with PR and 83.3% patients with RR overlapped with each other. At a median of 12.5 (3.4-19.5) months of follow-up, 13 of 17 patients (76.5%) with R0 resection were recurrence-free. No ≥3 toxicity was found. Besides high microsatellite instability, tumor mutation/neoantigen burden (TMB/TNB), mutation signatures (“DNA damage repair” and “DNA mismatch repair”) and related gene mutations (BRCA2, PRKDC, ATM, POLD1, POLE), several novel driver mutations (SSPO, TRPS1, and DOCK2) and copy number variants (DUSP15 loss, FDFT1 gain, and RBBP8NL loss) were related to MPR+ GC. The combination therapy decreased TMB/TNB, facilitated infiltration of active immune cells (CD4+ memory T, CD8+ T, activated and plasmacytoid dendritic cells, and M1 macrophage), and specifically boosted TCR clonality in MPR+ patients. Besides, numbers of mesenchymal stem cells decreased in MPR+ but increased in MPR- GC after the treatment. Conclusions: Combination of camrelizumab, apatinib, S-1 ± oxaliplatin is feasible, safe, and efficient in neoadjuvant/conversion therapy for cT4a/bN+ GC. It may remodel immune microenvironments and induce anti-tumor immune responses. Clinical trial information: NCT03878472. [Table: see text]

Outcomes in 36 Patients with Stage IIIA-N2 Squamous Cell Carcinoma of the Lung Treated with Nab-Paclitaxel Plus Carboplatin as Neoadjuvant Therapy: A Prospective Study from a Single Center

BackgroundWhether nab-paclitaxel plus carboplatin as neoadjuvant therapy can benefit patients with resectable squamous cell carcinoma of the lung remains unclear. This prospective study aimed to investigate outcomes in patients with stage IIIA-N2 squamous cell carcinoma of the lung treated with nab-paclitaxel plus carboplatin as neoadjuvant therapy.Material/MethodsPatients with stage IIIA-N2 squamous cell carcinoma of the lung were treated with nab-paclitaxel (100 mg/m2, days 1, 8, and 15) and carboplatin (5 mg/(mL·min), day 1) for two 21-day cycles. The patients were followed every 3 months for 2 years and every 6 months after that. The primary endpoint was the downstaging rate. Secondary endpoints included objective response rate (ORR), margin-free (R0) resection, pathologic complete response (pCR), progression-free survival (PFS), overall survival (OS), and safety.ResultsAmong the 36 enrolled patients, 33 completed neoadjuvant chemotherapy, and 23 underwent surgery. The preoperative ORR was 50.0% (18/36). R0 resection was achieved in 22 (95.7%) of 23 patients. Major pathologic response and pCR were achieved in 8 (34.8%) and 2 (8.7%) patients, respectively. The overall downstaging rate was 47.8% (11/23). The median follow-up was 39.8 (32.5–41.0) months. For patients who underwent surgery, the median PFS and OS were 31.4 (95%CI: 10.4-not reached (NR)) and 45.0 (95%CI: 22.6-NR) months, respectively. The most common adverse events were neutropenia, anemia, and leukopenia.ConclusionsThis study preliminarily indicated a favorable effect of nab-paclitaxel plus carboplatin as neoadjuvant therapy without significant adverse events for stage IIIA-N2 squamous cell carcinoma of the lung. Future randomized controlled trials are needed to verify these results.

Safety and Efficacy of Degradable Starch Microspheres Transcatheter Arterial Chemoembolization (DSM-TACE) in the Downstaging of Intermediate-Stage Hepatocellular Carcinoma (HCC) in Patients With a Child-Pugh Score of 8-9.

According to the EASL Guidelines for the management of hepatocellular carcinoma, transcatheter arterial chemoembolization is the first-line treatment recommended for intermediate-stage HCC. Furthermore, it is widely accepted that patients beyond the Milan criteria can be considered for a liver transplant after successful downstaging to within the Milan criteria. Response to downstaging treatments significantly influences not just drop-outs, but also the rate of post-transplantation tumor recurrences. TACE with degradable starch microspheres represents an alternative to conventional TACE with lipiodol and TACE with drug-eluting beads, and it leads to transient arterial occlusion allowing lower activation of hypoxia-inducible factors and less release of vascular endothelial growth factor, a promoter of neoangiogenesis, tumor proliferation, and metastatic growth. In patients with intermediate-stage HCC and a Child-Pugh score of 8 or 9, life expectancy may be dominated by cirrhotic liver dysfunction, rather than by the tumor progression itself; hence, locoregional treatments might also be detrimental, precipitating liver dysfunction to an extent that survival is shortened rather than prolonged. Data on tolerability, toxicity, and effectiveness of DSM-TACE are limited but encouraging. Between January 2015 and October 2020, 50 consecutive patients with intermediate-stage hepatocellular carcinoma and a Child-Pugh score of 8/9, who had undergone DSM-TACE as the first-line treatment, were eligible for the study. A total of 142 DSM-TACEs were performed, with a mean number of 2.84 procedures per patient. The mean time-to-downstaging was 19.2 months, with six patients successfully downstaged. OS was about 100% at six months, 81.8% at 12 months, and 50% at 24 months. Twenty-two patients experienced adverse events after chemoembolization. The median OS and safety of DSM-TACE in this study are comparable with other published investigations in this field. Furthermore, 12% of patients were successfully downstaged. Hence, the results of the current investigation demonstrate that DSM-TACE is effective and safe in intermediate-stage HCC, achieving an interesting downstaging rate. Such data were observed in the population subset with a Child-Pugh score of 8 or 9, in which life expectancy may be determined by cirrhotic liver dysfunction, so the achievement of a balance between the safety and efficacy profile of the TACE treatment is crucial.

Comparison of clinical outcomes in patients with localized or locally advanced urothelial carcinoma treated with neoadjuvant chemotherapy involving gemcitabine-cisplatin and high dose-intensity MVAC.

To compare the efficacy and safety of high dose-intensity combination of methotrexate, vinblastine, adriamycin and cisplatin (HD MVAC) with gemcitabine plus cisplatin (GC) as a neoadjuvant chemotherapy (NAC) in muscle-invasive bladder cancer (MIBC) or locally advanced upper tract urothelial cancer (UTUC). A retrospective analysis was conducted for patients with UC (cT2-4aN0-1M0) who received NAC from January 2011 and December 2017 at Asan Medical Center. Pathologic complete response (pCR), down-staging (< ypT2 and no N upstaging), disease-free survival (DFS), OS and safety were compared for each regimen. Out of a total of 277 patients, 176 patients received GC and 41 patients received HD MVAC. With the exception of age (patients receiving HD MVAC were younger; p = 0.002), other baseline characteristics were well balanced between groups. pCR rates were 27.0% for GC and 22.6% for HD MVAC (p = 0.62), and down-staging rate was 50.8% for GC and 58.1% for HD MVAC (p = 0.47). There were no differences in OS (72.1% vs 73.1% for GC vs HD MVAC; p = 0.58) and DFS (54.9% vs 63.3% for GC vs HD MVAC; p = 0.21) at 3years. HD MVAC with prophylactic G-CSF was associated with a higher incidence of febrile neutropenia (p < 0.001) than GC. The NAC regimen was not an independent prognostic factor for OS. Oncologic outcomes were not significantly different between the GC and HD MVAC when used as NAC in MIBC/UTUC.

Complete Transurethral Resection before Radical Cystectomy May Improve Oncological Outcomes

Objectives: The objective of this study was to assess the impact of complete transurethral resection of bladder tumors (TURBTs) before radical cystectomy on pathological and oncological outcomes of patients with muscle-invasive bladder cancer (MIBC) and high-risk non-MIBC. Materials and Methods: The charts of all patients who underwent radical cystectomy for bladder cancer in 2 academic departments of urology between 1996 and 2016 were retrospectively reviewed. Patients were divided into 2 groups according to the completeness of the last endoscopic resection before radical cystectomy: macroscopically complete transurethral resection (complete) or macroscopically incomplete transurethral resection (incomplete). The primary end point was the recurrence-free survival (RFS). Secondary end points included cancer-specific survival (CSS) and rates of pT0 and downstaging. Results: Out of 486 patients included for analysis, the TURBT immediately preceding radical cystectomy was considered macroscopically complete in 253 patients (52.1%) and incomplete in 233 patients (47.9%). In multivariate analysis, macroscopically complete TURBT was the strongest predictor of both pT0 disease (OR = 3.1; p = 0.02) and downstaging (OR = 7.1; p < 0.0001). After a median follow-up of 41 months, macroscopically complete TURBT was associated with better RFS (5-year RFS: 57 vs. 37%; p < 0.0001) and CSS (5-year CSS: 70.8 vs. 54.5%; p = 0.002). In multivariate analysis adjusting for multifocality, weight of endoscopic resection specimen, cT4 stage on preoperative imaging, interval between endoscopic resection and radical cystectomy, neoadjuvant chemotherapy, pT stage, and associated carcinoma in situ, macroscopically complete endoscopic resection remained the main predictor of better RFS (HR = 0.4; p = 0.0003) and the only preoperative factor associated with CSS (HR = 0.5; p = 0.01). Conclusion: A macroscopically complete TURBT immediately preceding radical cystectomy may improve pathological and oncological outcomes in patients with MIBC and high-risk MIBC.

Phase II trial of escalating doses of neoadjuvant atezolizumab for patients with non-metastatic urothelial carcinoma ineligible for cisplatin-based neoadjuvant chemotherapy.

442 Background: For patients (pts) with muscle-invasive bladder cancer (MIBC) who are ineligible for cisplatin-based chemotherapy (cisplatin), the standard of care option is radical cystectomy (RC) alone. This prospective clinical trial investigated the safety and efficacy of escalating doses of atezolizumab (ATZ) as neoadjuvant therapy prior to RC in pts with non-metastatic urothelial cancer. Methods: This single-arm, single institution, phase II trial investigated the administration of one (n = 6), two (n = 5) or three (n = 9) cycles of ATZ (1200 mg IV given every 3 weeks) in pts with MIBC who are either ineligible for or refused cisplatin prior to RC. Key inclusion criteria were urothelial carcinoma of the bladder (T2-T4a,N0-1,M0) and inability to receive cisplatin-based treatment (eGFR &lt; 60 mL/min, G≥2 neuropathy/hearing loss, pt decision). Pts with high-risk disease ( &gt; pT2 or LN+) at the time of RC were eligible to receive adjuvant ATZ for up to 16 total cycles. Primary efficacy endpoint was pathologic complete response (pCR; pT0N0). Important secondary endpoints were safety of treatment, rates of pathologic downstaging and biomarker assessments in serial tissue samples. Pts were followed for up to 2 years following RC. Results: Among 20 pts with MIBC, median age was 69 (range 61-81) and 75% were male. Most commonly pts were cisplatin-ineligible due to low GFR (35%), hearing loss (25%) or neuropathy (10%); remainder refused cisplatin (30%). At trial enrollment, pT2, pT3, and pT4 was present in 80%, 15%, and 5% of pts and 10% had enlarged pelvic lymph nodes ( &gt; 10 mm) on scans. All pts completed intended treatment cycles and all had RC within the defined timeframe ( &gt; 3 weeks from last and &lt; 12 weeks from first treatment). pCR at RC was 10% (2/20 pts), and was observed in pts receiving 1 and 2 cycles of ATZ. Pathologic downstaging (≤pT1N0) was achieved in 25% (5/20 pts) and observed across all three dose levels. Adjuvant ATZ was given to 8 pts. TRAEs of any grade during perioperative period occurred in 75% and G3 TRAEs in 10% (diarrhea, fecal incontinence). There were no G4 or G5 events. Median follow-up from the time of RC was 21.4 months at the time of data cutoff in 10/2020. Among evaluable pts, 1-year RFS and OS were 71% and 94% while 2-year RFS and OS were 64% and 75%. Conclusions: This prospective trial supports the safety and efficacy of ATZ as neoadjuvant therapy in MIBC. Although pCR and rates of downstaging were lower than what was previously reported in comparable neoadjuvant trials of checkpoint inhibitors in MIBC, pCRs in this trial were seen even in pts receiving only 1-2 doses of ATZ. Many pts had a durable recurrence-free period and all 4 evaluable pts who had pathologic downstaging were alive and disease free at 2 years post RC. Translational and biomarker work from this study is also being pursued. Clinical trial information: NCT02451423.

Phase II study of gemcitabine and split-dose cisplatin plus pembrolizumab as neoadjuvant therapy prior to radical cystectomy (RC) in patients with muscle-invasive bladder cancer (MIBC).

396 Background: Cisplatin-based neoadjuvant chemotherapy is standard of care in MIBC with improved pathologic response and overall survival (OS) compared to RC alone. Pembrolizumab (pembro) is active in high-risk non-muscle invasive and metastatic bladder cancer and is generally well tolerated. This phase II trial evaluated the safety and efficacy of gemcitabine and split-dose cisplatin (GC) + pembro as neoadjuvant therapy prior to RC (NCT02690558). Methods: Patients with clinical T2-4a N0/X M0 urothelial carcinoma of the bladder eligible for RC were enrolled. Patients received pembro 200mg on day 1 with cisplatin 35mg/m2 and gemcitabine 1000mg/m2 on days 1 and 8 every 3 weeks for 4 cycles, followed by RC within 4-8 weeks. The first 6 patients received full-dose cisplatin (70mg/m2 on day 1) and a lead-in pembro dose; this schedule was discontinued for excess toxicity. Primary endpoint was pathologic downstaging rate ( &lt; pT2) with the null and alternative hypothesis rates = 35% and 55%, respectively. Secondary endpoints were toxicity, pT0 rate, event free survival, and OS. Exploratory objectives include association of response with molecular subtype and post-treatment changes in immune microenvironment (predicted neoantigens, immune gene expression, and T cell receptor repertoire). Results: Between May 2016 and July 2020, 39 patients were enrolled (72% cT2, 23% cT3, 5% cT4a) with a median age of 66 and 82% male. Patients received a median of 4 cycles of therapy. All patients underwent RC except one who declined but is included in intention to treat analysis. Rate of &lt; pT2N0 was 56% (22/39) and pT0N0 rate was 36% (14/39). Most common adverse events (AEs) of any grade were thrombocytopenia (29/39; 74%), anemia (27/39; 69%), neutropenia (26/39; 67%), and hypomagnesemia (26/39; 67%). Most common grade 3/4 AEs were neutropenia (16/39; 41%), thrombocytopenia (13/39; 33%), febrile neutropenia (5/39; 13%), and anemia (4/39; 10%). One patient had new onset type 1 diabetes mellitus with ketoacidosis related to pembrolizumab and no patients required steroids for immune-related AEs. Nine patients (23%) discontinued GC + pembro due to AEs, including 4 of the 6 patients who received full-dose cisplatin with pembro lead-in. Survival data are not yet mature and correlative studies are ongoing. Conclusions: Neoadjuvant GC + pembro was generally safe and met its primary endpoint for improved pathologic downstaging. Correlative analyses are ongoing. Additional investigation of this combination is warranted. Clinical trial information: NCT02690558.

Abstract PS1-44: Impact of a standardized protocol for management of axilla after neoadjuvant chemotherapy in breast cancer patients at a cancer center

Abstract Background: Axillary lymph node status is one of the most important prognostic factors in breast cancer (BC). Neoadjuvant Chemotherapy (NACT) has been indicated for locally advanced tumors, and for HER2-positive and triple negative tumors larger than 2.0 and 1.0 cm, respectively, regardless of axillary status. This approach allows to assess biological response of the tumor, predicting prognosis and may permit more conservative surgeries in breast and axilla. However, there is no consensus about the best approach on management of axilla after NACT. Objective: To evaluate the rate of axillary downstaging after NACT in BC patients using a standardized protocol with a clip marker placement on positive lymph nodes prior to chemotherapy at a Cancer Center. Methods: This single-center, Institutional Review Board (IRB)-approved, retrospective study evaluated 471 BC patients who underwent NACT from January/2014 to December/2018. All included patients were evaluated for histological type, clinical T and N stages before NACT, modality of breast surgery (mastectomy vs. lumpectomy), type of axillary dissection (Axillary Lymph Node Dissection [ALND], sentinel lymph node biopsy [SLNB], or SLNB followed by ALND), placement or not of a clip marker in axillary lymph nodes before NACT, reason for the ALND and the pathological response by residual cancer burden (RCB) criteria. Patients were divided in two groups, before and after institution of a standardized protocol for axillary management after NACT in January/2017, which consists of: (1) biopsy of clinically suspect axillary lymph nodes before NACT, and placement of a clip marker in one positive lymph node in patients with 1-2 suspected lymph nodes (N1); (2) SLNB after NACT using blue dye and radioactive isotope injection; (3A) in the presence of clip marker in an axillary lymph node, confirmation of its extraction is performed through radiography of the surgical specimen and, (3B) in the absence of clip markers on axillary lymph nodes, removal of at least 03 sentinel lymph nodes should be performed; (4) no further axillary dissection is performed if all SLN are negative on frozen section analysis; any residual lymph node disease and/or absence of previously placed clip marker on SLNB specimen indicate ALND.Results: Patients’ mean age was 47 years (range 24-87 years), 67.2% (n=316) were cT2-T3, 83.5% (n=393) cN+ (N1 and N2), 62.6% (n = 295) had mastectomy. ALND was performed in 64.7% (n=303) patients, SLNB in 33.3% (n=156) and SLNB followed by ALND in 1.9% (n=9). In the subgroup of N+ patients (n=385), it was possible to perform SNB in 25.6% (n=98). 165 of 471 patients (35%) were included in standardized protocol for axillary management; the rate of SLNB in N+ patients was statistically higher in this group when compared to patients treated before the implementation of the protocol (34.4% vs. 22.8%; p=0.025).Conclusion: The results of the present study demonstrate a significant increase in sparing ALND after the implementation of a standardized protocol for management of axilla after NACT. However, further multi-institutional studies are still needed to support its widely adoption, as well as clinical trials to assess overall and disease-free survival in those patients who had omitted ALND after NACT. Citation Format: Marina de Paula Canal, Caroline Rocha, Marina Sonagli, Almir Bitencourt, Solange Sanches, Monique Tavares, Cynthia Osório, Fabiana Baroni Makdissi. Impact of a standardized protocol for management of axilla after neoadjuvant chemotherapy in breast cancer patients at a cancer center [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-44.

Neoadjuvant hormone therapy for patients with high-risk prostate cancer: a systematic review and meta-analysis.

This study aimed to identify the pathological outcomes and survival benefits of neoadjuvant hormone therapy (NHT) combined with radical prostatectomy (RP) and radiotherapy (RT) administered to patients with high-risk prostate cancer (HRPCa). We searched PubMed, Embase, and the Cochrane Library for studies comparing NHT plus RP or RT with RP or RT alone, administered to patients with HRPCa. We used a random-effects model to compute risk estimates with 95% confidence intervals (CIs) and quantified heterogeneity using the I2 statistic. Subgroup and sensitivity analyses were performed to identify potential sources of heterogeneity. We selected 16 studies. NHT before RP significantly decreased lymph node involvement (risk ratio [RR] = 0.69, 95% CI: 0.56–0.87) and increased the rates of pathological downstaging (RR = 2.62, 95% CI: 1.22–5.61) and organ-confinement (RR = 2.24, 95% CI: 1.54–3.25), but did not improve overall survival and biochemical progression-free survival (bPFS). The administration of NHT before RT to patients with HRPCa was associated with significant benefits for cancer-specific survival (hazard ratio [HR] = 0.51, 95% CI: 0.39–0.68), disease-free survival (HR = 0.51, 95% CI: 0.44–0.60), and bPFS (HR = 0.54, 95% CI: 0.46–0.64). Short-term NHT combined with RT administered to patients with HRPCa conferred significant improvements. Although the advantage of local control was observed when NHT was administered before RP, there was no significant survival benefit associated with HRPCa. Therefore, short-term NHT combined with RT is recommended for implementation in standard clinical practice but not for patients who undergo RP.

Natural history, response to systemic therapy, and genomic landscape of plasmacytoid urothelial carcinoma

BackgroundPlasmacytoid urothelial carcinoma (PUC) is a rare, aggressive histologic variant of urothelial cancer characterised by a diffuse growth pattern and CDH1 mutation. We studied the efficacy of preoperative platinum-based chemotherapy in nonmetastatic PUC and immune checkpoint inhibitors (ICIs) in advanced PUC.MethodsCases of nonmetastatic PUC and advanced PUC treated with ICIs at our institution were identified. Outcomes were compared to those of a published cohort of patients with urothelial carcinoma not otherwise specified.ResultsWe identified 81 patients with nonmetastatic PUC. Of the patients with localised disease who underwent neoadjuvant chemotherapy, pathologic complete response and downstaging rates were 12 and 21%, respectively. Pathologic downstaging was not associated with significant improvement in clinical outcomes. Up to 18% of localised disease and 28% of locally advanced cases had unresectable disease at the time of surgery. ICI-treated advanced PUC (N = 21) had progression-free and overall survival of 4.5 and 10.5 months, respectively, and a 38% response rate. FGFR3 and DNA damage response gene alterations were observed in 3 and 15% of cases, respectively.ConclusionsPUC is associated with high disease burden and poor chemosensitivity. Increased awareness and recognition of this disease variant will allow for new treatment strategies.

Evaluation of the Efficacy and Toxicity of Radiotherapy for Type III-IV Portal Vein Tumor Thrombi.

Background:Type Ⅲ and Ⅳ portal vein tumor thrombi (PVTT) cannot be removed through surgery, and no effective therapeutic procedure is available. Type Ⅲ/Ⅳ PVTT can be downstage to type I/II PVTT by using Radiotherapy, and can further be can be removed surgically. Thus, radiotherapy may be an effective treatment for type Ⅲ/Ⅳ PVTT. This study aims to evaluate the efficacy and toxicity of radiotherapy for type III-IV PVTT.Methods:This prospective study was conducted from August 1, 2017, to September 30, 2019, for patients with type Ⅲ and Ⅳ PVTT. Patients received radiotherapy with a target dose of 50Gy/25f or 59.5Gy/17 f. Advanced radiological technique such as image fusion technique for CT image and MRI image were utilized to produce more precise lesion localization, and limit the dose to organs at risk in order to get a better downstage rate and less adverse complications.Results:Nine (9) patients with type Ⅲ PVTT and 5 patients with type Ⅳ PVTT were included in this study. 12 patients received a radiotherapy dose of 50Gy/25f, 2 patients received 59.50Gy/17 f. After radiotherapy, 92.9% of patients with PVTT were successfully downstage to type II/I. In patients with primary hepatocellular carcinoma, 8 patients (accounting 88.9%) achieved down-stage. 5 patients with other types of tumors achieved downstage which accounts 100%. In addition, none of the 14 patients observed radiation hepatitis and radiation liver failure. And none of the patients developed gastrointestinal ulcers and thrombocytopenia.Conclusion:Radiotherapy is a suitable treatment measure for type Ⅲ and Ⅳ PVTT to get downstage and make the opportunity for surgery. Image fusion technology for precise lesion location such as CT-MRI image fusion, and strict dose limitation of organ at risk, contributed to the improvement of radiotherapy efficiency and the significant decrease in adverse complications.

Efficacy of conversion therapy on initially unresectable locally advanced rectal cancer.

Background and purpose: Research on the efficacy of conversion therapy for initially unresectable mid-low rectal cancer (IURC) remained limited. This study aimed to assess the efficacy and safety of the conversion regimen for IURC and analyze the long-term outcomes of these patients.Methods: We retrospectively analyzed the data of clinically diagnosed IURC patients who received conversion therapy between October 2010 and April 2017. The conversion therapy consisted of long-term radiation, concurrent chemotherapy, delayed surgery and consolidation chemotherapy. The primary end point was the rate of R0 resection, and other short- and long-term outcomes were analyzed.Results: Sixty-one patients were enrolled in this study. After conversion therapy, 51 (83.6%) patients received R0 resection. The rates of pathologic complete response and downstaging were 16.4% and 62.3%, respectively. The rate of grade 3-4 chemoradiotherapy-related toxicity events was 13.1%. The overall survival at 3 years was 75.4% in all patients, and the disease-free survival at 3 years was 72.5% in patients who received R0 resection.Conclusion: The conversion regimen showed a high conversion resection rate and good survival outcomes in IURC patients, and might benefit the patients if recommended in clinical practice.