High-risk Histologic Features Research Articles

Uterine Inflammatory Myofibroblastic Tumors: p16 as a Surrogate for CDKN2A Deletion and Predictor of Aggressive Behavior.

Uterine inflammatory myofibroblastic tumors (IMTs) are rare mesenchymal neoplasms of uncertain malignant potential. Aside from the recently described risk stratification score, which has not been validated by other studies, and rare reports of aberrant p16 expression in malignant tumors, there are no criteria to reliably predict behavior. Herein, we evaluated the clinicopathologic features and p16 expression patterns in 30 IMTs, with genomic profiling performed in a subset (13 malignant, 3 benign). Fifteen patients had malignant IMTs, defined by extrauterine disease at diagnosis (n=5) or recurrence (n=10; median: 24 mo). Patients ranged from 8 to 65 (median: 51) years and tumors from 6 to 22 (median: 12.5) cm. In primary tumors (n=13), infiltrative borders were noted in 10, moderate/severe cytologic atypia in 9, tumor cell necrosis in 7, and lymphovascular invasion in 6, while mitoses ranged from 0 to 21 (median: 7) per 10 high-power fields. In contrast, 15 patients with benign IMTs ranged from 28 to 65 (median: 44) years, with follow-up of 18 to 114 (median: 41) months. Tumors ranged from 1.9 to 8.5 (median: 5.5) cm, 2 demonstrated infiltrative borders, and 1 had moderate cytologic atypia. No other high-risk histologic features were observed. Application of the previously described clinicopathologic risk stratification score in all primary IMTs with complete data (n=18) classified 8 as high-risk (all malignant), 8 as intermediate-risk (3 malignant, 5 benign), and 2 as low-risk (benign). p16 was aberrant in all malignant IMTs, with <1% expression noted in 10, overexpression (>90%) in 4, and subclonal loss in 1; all benign tumors had patchy staining (20% to 80%; median 50%). Molecular analysis detected CDKN2A deletions in 8 of 9 tumors with <1% p16 expression, while the other harbored a TERT promoter mutation. TERT promoter mutations were also identified in 2 of 3 IMTs with p16 overexpression. Neither of these alterations was detected in the 3 sequenced benign IMTs. Thus, we recommend performing p16 on all uterine IMTs, which, combined with the risk stratification score, is a promising and cost-effective tool for predicting CDKN2A status and outcome in these patients. It may be particularly useful for tumors with incomplete information for risk stratification (ie, morcellated tumors) and for further stratifying intermediate-risk IMTs when sequencing is unavailable.

Radiation therapy of renal cell carcinoma skeletal metastases – Does histologic subtype predict progression?: Renal cell histology and radiotherapy response

IntroductionThis investigation assessed whether the following factors were associated with radiographic local progression in bone metastases from renal cell carcinoma (RCC): (1) high-risk histologic features (2) lesional surgery (3) biologically effective dose (BED) of radiation therapy. Methods and materialsA single-institution database identified all patients who underwent surgery and radiation therapy for bone metastases from RCC to the appendicular skeleton and pelvis from 2006 to 2016. Thirty-six patients underwent radiotherapy for 80 metastases. While all patients had surgical stabilization, 17/36 also had lesional surgery to address the metastatic lesion. Progression of each individual lesion was determined using the application of RECIST criteria to imaging at last follow-up. ResultsThe rate of progressive disease was 8/25 (32%) in the high-risk group versus 5/55 (9%) in the standard-risk group (p ​= ​0.019). The rate of progression among high-risk metastases undergoing lesional surgery was 0/9 versus 8/16 (50%) having non-lesional surgery (p ​= ​0.0218). The rate of progression among standard-risk metastases undergoing lesional surgery was 1/16 (6%) versus 4/39 (10%) with non-lesional surgery (p ​= ​1.00). High-risk histologic features (OR: 10.592, 95% confidence interval: 1.347–83.271, p ​= ​0.025) and as well as a reduction in risk with every additional Gray of BED (OR: 0.902, 95% confidence interval: 0.827–0.984, p ​= ​0.021) were found to predict progressive disease. ConclusionsBone metastases from renal cell carcinoma with high-risk histologic features are associated with less favorable response to radiotherapy than those with standard-risk histology. Delivery of a higher BED was associated with lower odds of progression.

What do we miss in this Orbital Retinoblastoma?

Introduction : Orbital retinoblastoma (RB) is a dire event with a bleak prognosis. This report highlights the severe complications of retinoblastoma resulting from insufficient diagnostic and treatment efforts due to inadequate medical resources and socio-economic challenges.&#x0D; Case Illustration : A 4-year-old boy was brought in with swelling on his left eye socket and jaw, present for two months.He had exhibited leukocoria followed by proptosis 12 months prior and underwent enucleation without dermato-fat graft (DFG) five months ago. Histopathology revealed retinoblastoma without optic nerve invasion. Despite referral to a regional hospital for chemotherapy, he did not receive treatment due to socio-economic constraints. Two months post-operation, the left eye prosthesis spontaneously dislodged, accompanied by an enlarging eye and a left jaw mass. An ophthalmologic assessment disclosed a mass in the left orbital socket, while the right eye appeared normal. A CT scan identified masses in the left orbit, parotid, and masticator spaces, as well as bilateral colli lymphadenopathy. The patient was diagnosed with residual retinoblastoma and received chemotherapy.&#x0D; Discussion : Imaging is crucial in proptosis patients to determine tumor extent and management strategies. The standard approach involves initial chemotherapy, surgery, radiotherapy, and additional chemotherapy. High-risk histological features (HHRF) also warrant chemotherapy, although the presence of such features remains undetermined in this case. Employing multiple treatment modalities may enhance prognosis.&#x0D; Conclusion : Thorough examination and management are essential in retinoblastoma cases. Patient family education and diligent care play a crucial role in preventing the progression and spread of retinoblastoma.

Low local recurrence rates following marginal surgical resection of non-coelomic Atypical Lipomatous Tumours/Well-differentiated Liposarcomas

IntroductionHigh rates of local recurrence (LR) have been reported following resection of extremity Atypical lipomatous tumours/Well-differentiated liposarcomas (ALTs). This retrospective study of patients who underwent resection of primary deep extremity and trunk ALTs at a specialist sarcoma centre aims to assess morbidity and factors associated with low local recurrence rates (LRR). MethodsTo review a homogeneous cohort of patients with low-grade disease, tumours with known high-risk histological features were excluded. Prognostic variables potentially influencing local recurrence (LR) (age, size, site, margin status, and histological findings) were analysed. Endpoints were LR, distant recurrence (DR) and local disease-free survival (LDFS). Results127 patients were identified, with median follow-up of 54 months (0–235). Median tumour size was 17.5 cm (5–36). 85 % occurred in the lower limb. 93.7 % underwent marginal resection. No patients received radiotherapy. Median hospital stay was 3 days (0–16). 7.9 % returned to theatre for evacuation of haematoma or infected seroma and 18.1 % had outpatient seroma aspiration. Surgical margins were R0/R1 in 93.7 % of patients and R2 in 6.3 % with a LR rate of 8.4 % and 75 % respectively at median time of 54 months. One- and 5-year LDFS was 100 % and 88.4 %, respectively. DR rate was 0.8 % (1/127) this patient had pleomorphic liposarcomatous transformation on recurrence and subsequently developed distant metastases. No patients died of disease. ConclusionFunction-preserving marginal resection of non-coelomic ALTs has low morbidity, low LR and extremely low rates of distant relapse. Patients with lower limb ALT were found to have significantly lower LR, which may impact follow-up protocols.

Clinicopathologic Features of Prostate Cancer with Mesorectal Lymph Node Involvement on PSMA or Fluciclovine PET/CT

Advanced PET imaging has shown more prevalent mesorectal lymph node (LN) involvement in prostate cancer than previously appreciated. The clinical features predicting risk for mesorectal involvement are not well established and the prognostic impact is unclear. This may have implications on management including radiotherapy field design. This study aims to identify clinical and pathologic characteristics associated with mesorectal involvement identified on PSMA or fluciclovine PET/CT. We conducted a single institution retrospective review of prostate cancer patients with F-18 fluciclovine, F-18 piflufolastat, or Ga-68 gozetotide PET between January 2020 and 2023 demonstrating tracer-avid mesorectal LN in the setting of newly diagnosed disease (ND) or biochemical failure after curative-intent therapy (BF). Clinical characteristics, pathologic findings, and early clinical outcomes were reviewed. We identified 16 ND and 34 BF patients with uptake in at least one mesorectal LN on PET. For ND patients, clinical features at initial diagnosis were median PSA of 35.2 (range 9.6-659), median grade group 5, and 87% with clinical or radiographic T3/T4 disease. Radiographic PET staging among ND patients (excluding mesorectal LNs) were 19% N0M0, 25% N1M0, 56% as N1M1. For BF patients, clinical features at initial diagnosis were median PSA 9.2 (range 4.1-90) and median grade group 4. Primary treatment was prostatectomy in most (91%), with a high rate of high-risk features: 68% pT3-4, 28% pN1, and 32% had persistent detectable postop PSA. Radiographic PET staging among BF patients (excluding mesorectal LNs) were 29% N0M0, 38% N1M0, 12% N0M1, and 21% as N1M1. High-risk histologic features (cribriform, intraductal, ductal, or neuroendocrine) were identified in 88% of ND and 48% BF patients. Of these patients, 86% had cribriform pattern. Median PSA prior to PET for ND and BF patients was 37.0 (range 8.5-659) and 1.9 (0.2-11.1). Median interval from initial therapy to PET for BF patients was 4.4yr (range 0.2-19.7). Median follow-up post-PET was 8.7mo (range 3.4-29) for ND and 8.8mo (range 0-76) for BF patients. Of patients with M0 PET staging, none of the 7 ND patients developed DMs, and 1 of 23 BF patients developed DM after 4 yrs. In this analysis of prostate cancer patients with mesorectal involvement, we found a high incidence of high grade, T3-4 disease, and cribriform pattern, especially in ND patients. For BF patients, there was a high incidence of pT3-4 and pN1 disease at time of initial treatment. Overall, most patients had concurrent regional nodal disease on PET. Longer follow up of clinical outcomes and comparison to high-risk patients without mesorectal LN involvement is needed to understand the prognostic significance and predictors of mesorectal LN spread. Additional studies are needed to identify patients at highest risk in whom elective coverage of mesorectal lymphatics with elective pelvic nodal RT may be warranted.

Fertility sparing therapy in women with lymph node negative cervical cancer >2cm – oncologic and fertility outcomes of neoadjuvant chemotherapy followed by radical vaginal trachelectomy

ObjectiveSimple or radical trachelectomy are accepted fertility sparing therapies for patients diagnosed with cervical cancer ≤2 cm. In patients with larger tumors a fertility sparing concept is considered experimental. The...

Completion Total Mesorectal Excision: A Case-Matched Comparison With Primary Resection.

The aim of this study was to compare the perioperative and oncological results of completion total mesorectal excision (cTME) versus primary total mesorectal excision (pTME). Early-stage rectal cancer can be treated by local excision alone, which is associated with less surgical morbidity and improved functional outcomes compared with radical surgery. When high-risk histological features are present, cTME is indicated, with possible worse clinical and oncological outcomes compared to pTME. This retrospective cohort study included all patients that underwent TME surgery for rectal cancer performed in 11 centers in the Netherlands between 2015 and 2017. After case-matching, we compared cTME with pTME. The primary outcome was major postoperative morbidity. Secondary outcomes included the rate of restorative procedures and 3-year oncological outcomes. In total 1069 patients were included, of which 35 underwent cTME. After matching (1:2 ratio), 29 cTME and 58 pTME were analyzed. No differences were found for major morbidity (27.6% vs 19.0%; P = 0.28) and abdominoperineal excision rate (31.0% vs 32.8%; P = 0.85) between cTME and pTME, respectively. Local recurrence (3.4% vs 8.6%; P = 0.43), systemic recurrence (3.4% vs 12.1%; P = 0.25), overall survival (93.1% vs 94.8%; P = 0.71), and disease-free survival (89.7% vs 81.0%; P = 0.43) were comparable between cTME and pTME. cTME is not associated with higher major morbidity, whereas the abdominoperineal excision rate and 3-year oncological outcomes are similar compared to pTME. Local excision as a diagnostic tool followed by completion surgery for early rectal cancer does not compromise outcomes and should still be considered as the treatment of early-stage rectal cancer.

Evaluation of prognostic prediction ability of the novel Japanese risk factor scoring system in a Japanese cohort of resectable cutaneous squamous cell carcinoma: A retrospective cross-sectional study.

Japanese patients with very high-risk cutaneous squamous cell carcinomas (cSCCs), based on the National Comprehensive Cancer Network guidelines, have been reported to display a higher cumulative incidence of relapse and disease-specific death (DSD) than those with high-risk cSCC. Therefore, prognosis prediction is crucial for Japanese patients with very high-risk cSCCs. Herein, we aimed to evaluate the prognostic prediction ability of our novel Japanese Risk Factor Scoring Systems (JARF scoring) in a Japanese cohort of cSSC patients. Data of 424 Japanese patients with resectable very high-risk cSCCs were analysed. We compared the prognostic ability of the following three staging systems: Brigham and Women's Hospital (BWH) tumour staging, number of NCCN very high-risk factors, and JARF scoring, including recurrent tumour, high-risk histological features, deep tumour invasion and lymphatic or vascular involvement as risk factors. The prognostic ability of these staging systems was evaluated according to the cumulative incidence of local recurrence (LR), regional lymph node metastasis (RLNM), DSD, and overall survival (OS). When BWH staging was used, high T stage led to significantly poor outcomes only in the cumulative incidence of RLNM (p = 0.01). The presence of very high-risk NCCN factors led to significantly poor outcomes in terms of RLNM (p = 0.03) and OS (p = 0.02). Meanwhile, a high number of risk factors in the JARF scoring system clearly led to poor outcomes in terms of LR (p = 0.01), RLNM (p < 0.01), DSD (p = 0.03), and OS (p < 0.01). The JARF scoring system may accurately predict the risk of recurrence and death in very high-risk cSCC patients in Japan.

Clinical outcomes of squamous cell carcinomas following complete saucerization with negative margins: Retrospective case series from 2010-2022

Clinical outcomes of squamous cell carcinomas following complete saucerization with negative margins: Retrospective case series from 2010-2022

235P Evaluation of a prognostic model for head and neck cutaneous squamous cell carcinoma using a cumulative number of risk factors

Cutaneous squamous cell carcinoma (cSCC) is the second most common cutaneous malignant tumor, occurring frequently in the head and neck. The latest National Comprehensive Cancer Network (NCCN) Guidelines classify cSCC into low-, high-, and very-high-risk groups using multiple risk factors. There were no detailed and accurate prognostic models for the newly established “very-high-risk” group. We identified the following four important risk factors for local relapse, nodal relapse, and SCC-related death in a previous study: recurrent tumor, high-risk histologic features, >6-mm tumor thickness or invasion beyond the subcutaneous fat layer, and lymphatic or vascular involvement.

Role of Peri-operative Chemotherapy in Stage II (pT2N0) Gallbladder Cancers

BackgroundEvidence for adjuvant chemotherapy in gallbladder cancer (GBC) is conflicting, with a postulated beneficial effect reported in T2 stage or higher, and node-positive tumours. This study aims to assess the survival benefit of peri-operative chemotherapy in stage II (pT2N0) GBCs. MethodsA retrospective analysis of stage II GBCs who underwent curative surgical resection was done. Patients receiving neo-adjuvant therapy (NACT) prior to resection of the gallbladder primary were excluded. Primary endpoint was disease-free survival, and outcomes of patients who received chemotherapy were compared to those who did not. Survival curves were plotted using a Kaplan–Meier analysis and difference between the survival curves was analysed using a log-rank test. ResultsTwo hundred seventy-six patients of stage II GBC were included, of whom 188 (68.1%) received chemotherapy and 88 (31.8%) did not. Forty-one (21.8%) patients received chemotherapy in the neo-adjuvant setting. There was no significant difference in the survival of patients who did and did not receive chemotherapy (5-year DFS 67.8% vs 66%, p = 0.795). There was no significant difference in the survival of patients who received chemotherapy in the adjuvant or neo-adjuvant setting (5-year DFS 66.4% vs 71.8%, p = 0.541). There was no statistically significant difference in the survival of patients with high-risk histologic features and who did and did not receive chemotherapy (3-year DFS 72.4% vs 56%; p = 0.379). ConclusionsRoutine use of chemotherapy, either in the adjuvant or neo-adjuvant setting, offers no survival advantage in stage II (pT2N0) gallbladder cancers.

A decision support framework for postoperative radiotherapy in patients with pathological N2 non-small cell lung cancer

IntroductionPostoperative radiotherapy (PORT) plays a highly controversial role in pathological N2 (pN2) non-small cell lung cancer (NSCLC) disease. Recent studies reveal that not all patients can benefit from PORT. Further research is needed to identify predictors of PORT. MethodsA total of 1044 pathologic stage T1-3N2M0 NSCLC patients were analyzed. Risk factors of distant metastasis were identified by the log-rank tests and the multivariable Cox models. We integrated risk factors of distant metastasis and our previously published loco-regional recurrence (LRR) related prognostic index into a decision support framework (DSF) to predict the outcomes of PORT. An independent cohort was used to validate the DSF. ResultsWe defined patients with more than two of three identified LRR-related features (heavy cigarette smoking history, clinical N2 status, and more than four positive lymph nodes) as a high LRR risk group. We found the high-intermediate-risk histological type (with micropapillary and/or solid components) was associated with a higher risk of distant metastasis (HR = 1.207, 95 % CI 1.062 to 1.371, P = 0.0038), but not LRR. We built the DSF by combining these two types of features. Patients were stratified into four groups by using the DSF. PORT significantly improved OS only in the subgroup without high-risk histological features (without micropapillary or solid components) and with a high risk for LRR (three-year OS: 66.7 % in the PORT group vs 50.2 % in the non-PORT group; P = 0.023). ConclusionsA particular pN2 subgroup with a high risk of LRR and without micropapillary or solid components could benefit from PORT.

Analysis of metastases rates during follow-up after endoscopic resection of early “high-risk” esophageal adenocarcinoma

After endoscopic resection (ER) of early esophageal adenocarcinoma (EAC), the optimal management of patients with high-risk histologic features for lymph node metastases (ie, submucosal invasion, poor differentiation grade, or lymphovascular invasion) remains unclear. We aimed to evaluate outcomes of endoscopic follow-up after ER for high-risk EAC. For this retrospective cohort study, data were collected from all Dutch patients managed with endoscopic follow-up (endoscopy, EUS) after ER for high-risk EAC between 2008 and 2019. We distinguished 3 groups: intramucosal cancers with high-risk features, submucosal cancers with low-risk features, and submucosal cancers with high-risk features. The primary outcome was the annual risk for metastases during follow-up, stratified for baseline histology. One hundred twenty patients met the selection criteria. Median follow-up was 29 months (interquartile range, 15-48). Metastases were observed in 5 of 25 (annual risk, 6.9%; 95% confidence interval [CI], 3.0-15) high-risk intramucosal cancers, 1 of 55 (annual risk, .7%; 95% CI, 0-4.0) low-risk submucosal cancers, and 3 of 40 (annual risk, 3.0%; 95% CI, 0-7.0) high-risk submucosal cancers. Whereas the annual metastasis rate for high-risk submucosal EAC (3.0%) was somewhat lower than expected in comparison with previous reported percentages, the annual metastasis rate of 6.9% for high-risk intramucosal EAC is new and worrisome. This calls for further prospective studies and suggests that strict follow-up of this small subgroup is warranted until prospective data are available.

Thyroid lobectomy for low-risk thyroid cancers.

The 2016 American Thyroid Association (ATA) guidelines proposed thyroid lobectomy for low-risk differentiated thyroid cancer (DTC); however, this approach is yet to be widely adopted. The aim of the study was to review our practice over three years following the publication of these guidelines identifying patients who underwent lobectomy-only for low-risk DTC in two regional units in the same multidisciplinary team (MDT). A retrospective review of patients who were operated between January 2016 and December 2018 was carried out. In total, 288 patients undergoing thyroid surgery were included. The preoperative distribution of cytology was: Thy 1 or 2 in 46, THY3a in 57, THY3f in 154, THY4 in 18 and THY5 in 13 patients. Median size of nodules was 26mm (range 1-70mm). DTC was diagnosed in 95 patients (33%). Overall, 39% (n = 37) of patients underwent completion thyroidectomy according to ATA recommendations on size or adverse histological features. The only variable associated with likelihood of completion was tumour size (p < 0.05, OR 1.14). Ten patients were discharged following surgery with no further follow-up as they had T1a/b well-differentiated DTC with no high-risk histological features. Lobectomy-only appears to be the current surgical practice in two-thirds of patients presenting to our regional units with differentiated thyroid carcinoma. In the context of the current drive to reduce the extent of treatment for low-risk thyroid cancer, there is a need for a more homogeneous approach to these patients and for protocols for long-term follow-up after lobectomy-only.

A radiogenomics application for prognostic profiling of endometrial cancer

Prognostication is critical for accurate diagnosis and tailored treatment in endometrial cancer (EC). We employed radiogenomics to integrate preoperative magnetic resonance imaging (MRI, n = 487 patients) with histologic-, transcriptomic- and molecular biomarkers (n = 550 patients) aiming to identify aggressive tumor features in a study including 866 EC patients. Whole-volume tumor radiomic profiling from manually (radiologists) segmented tumors (n = 138 patients) yielded clusters identifying patients with high-risk histological features and poor survival. Radiomic profiling by a fully automated machine learning (ML)-based tumor segmentation algorithm (n = 336 patients) reproduced the same radiomic prognostic groups. From these radiomic risk-groups, an 11-gene high-risk signature was defined, and its prognostic role was reproduced in orthologous validation cohorts (n = 554 patients) and aligned with The Cancer Genome Atlas (TCGA) molecular class with poor survival (copy-number-high/p53-altered). We conclude that MRI-based integrated radiogenomics profiling provides refined tumor characterization that may aid in prognostication and guide future treatment strategies in EC.

Radiotherapy in the Adjuvant and Advanced Setting of CSCC.

The use of radiotherapy for cutaneous squamous cell carcinoma (CSCC) has solid historical roots. It is used with patients who are not suitable for surgery, with patients with high-risk histological features in the adjuvant setting, and in palliative care. The aim of this article is to summarize and provide a radiation therapy overview on the indications, effectiveness, and potential adverse events of radiotherapy in the adjuvant and advanced setting of CSCC. We performed a comprehensive literature review on PubMed, adopted as our biomedical literature database. Articles were selected based on their date of publication (in the last 30 years) and relevance. Radiotherapy (RT) can safely be used to manage non-surgical patients and high-risk patients in the advanced CSCC setting. The remarkable progress of delivery techniques has greatly improved the effectiveness and toxicity profile of RT treatments. From 2D techniques to intensity modulated radiation therapy (IMRT), and brachytherapy, all RT techniques have greatly advanced. To improve acute and chronic side effects, a deeper care has been used. As regards CSCC, several dose fractionations and schedules have been suggested, in line with the patient's age and medical conditions. RT is a fundamental and constantly evolving therapeutic option in the treatment of CSCC, to minimize the risk of recurrence and metastases in the adjuvant setting and in the exclusive treatment for non-surgical patients. Patients' selection is crucial, together with and a collaborative team working approach among the specialists involved in disease management in the perspective of the best multidisciplinary assessment.

S220 Cancer-Specific 5-Year Survival Following Endoscopic Polypectomy versus Surgery for Malignant Colorectal Polyps

Introduction: Current guidelines recommend polyp resection strategies, endoscopic resection (ER) or surgical resection (SR) based on high-risk histological features and depth of invasion to ensure complete removal of the malignant lesion, minimizing the risk of progression through micrometastasis. Data comparing cancer-specific survival following ER or SR for localized malignant polyps based on the AJCC staging (Stage 0, I & II & grade) are scarce. Methods: We used the Surveillance Epidemiology and End Results (SEER) database (2004-2015) on patients diagnosed with at least a single malignant colorectal polyp (Table) on the colonoscopies performed for any indication or screening. Data extraction was through a case listing session using SEER*Stat v8.3.9 on combined SEER 18 incidence registries using specific codes for CRC polyps with cancer. Statistical analysis was performed using SPSS v27 for Mac. Results: A total of 63,147 patients with a diagnosis of a colorectal polyp with a malignant component were identified. The mean age was 47.48 years (± 12.15 SD), 45.6% were females. T stages ranged T1-T3. Patients with stage 0 (carcinoma in situ) polyps showed equivalent 5-year cancer-specific survival regardless of ER or SR (mean 170 vs 169 months, 94.2% vs 93.7%, P=0.429, Figure 1A). Stage I and II patients showed superior 5-year survival with SR than ER (mean 165 vs 159 months, 91.1% vs 88%, p< 0.001, Figure 1B). Patients with well-differentiated histological grade demonstrated no survival differences regardless of ER or SR (mean 165 vs 166 months, 92.7% vs 93%, P=0.175, Figure 1C). In contrast, those with polyps of poor differentiation or anaplastic features showed superior 5-year cancer-specific survival with SR than ER (mean 161 vs 145months, 90% vs 88%, P=< 0.001, Figure 1E). Patients with polyps of moderate differentiation showed superior 5-year cancer-specific survival with SR compared with ER (mean 164 vs 159months, 92% vs 90% p< 0.001, Figure 1D) Conclusion: Our results show that cancer-specific survival improved in patients with malignant polyps with AJCC Stage I or II who underwent SR compared with ER, but not Stage 0 (carcinoma in situ). Another novel finding was superior 5-year cancer-specific survival in patients with polyps of moderately-differentiated histological grade, in addition to poorly differentiated and anaplastic grades, which has not been reported before. These novel findings warrant further corroboration from well-constructed clinical trials.Figure 1.: Five-year cancer specific survival comparing endoscopic resection versus surgical resection for colorectal polyps by cancer stage and histological grade.Table 1.: Number of patients diagnosed with polyps with a malignant component by stage and year of diagnosis.

Will a flexi-sig' do? A retrospective review of colonoscopies indicated by diverticulitis alone.

The incidence of colonic diverticulitis is increasing. In Australia the majority of diverticulitis occurs in the left colon and patients typically undergo colonoscopy following an attack. At present debate exists regarding the utility of this costly procedure and a flexible sigmoidoscopy has been proposed as a cheaper, less invasive alternative. This paper seeks to examine whether significant pathology is being detected in the right and transverse colon to warrant colonoscopy, as opposed to a flexible sigmoidoscopy. A retrospective review of colonoscopies performed between August 2016 and August 2018, indicated by diverticulitis alone, performed in a single Australian metropolitan hospital. 189 patient colonoscopies were reviewed in combination with the pathology forms. Only 1 primary colonic malignancy was detected, found in the left colon. 110 traditional adenomas and 35 sessile serrated adenomas were detected. 41.8% of patients had a polyp detected with an average of 1.9 polyps per patient. 38.6% of polyps were resected from the left colon while 61.4% were removed from the right and transverse colon. In total 30 polyps > 10mm or with high-risk histological features were resected, 18 (60%) from the left colon and 12 (40%) from the right and transverse. 20 patients (10.6%) met the criteria for high-risk adenomas and 50% of those had > 40% of their polyps in the right and transverse colon. There was no significant difference in age between patients with polyps and those without. Despite over half the patients having no polyps and only one left sided malignancy. This study demonstrates that the right and transverse colon is responsible for over 50% of the polyps removed and similar proportion of the advanced polyps. Where endoscopic surveillance after acute colonic diverticulitis is performed, this study supports the use of colonoscopy and cautions against flexible sigmoidoscopy alone.

Comparison of long-term recurrence-free survival between primary surgery and endoscopic resection followed by secondary surgery in T1 colorectal cancer

We aimed to investigate whether endoscopic resection of T1 colorectal cancer (CRC) before surgery (secondary surgery) unfavorably affects long-term recurrence-free survival (RFS) compared with surgery without prior endoscopic resection (primary surgery). We reviewed the medical records of patients who underwent radical surgery for T1 CRC with high-risk histologic features at a tertiary referral hospital in Korea between 2011 and 2016. The primary outcome was RFS. We performed 2 types of propensity score (PS) analyses to control for confounders. Of 852 patients, 388 underwent primary surgery and 464 secondary surgery. During the median follow-up period of 57.0 months (range, 41.0-63.0), cancer recurred in 18 patients (2.1%). The 5-year RFS rates did not differ between the primary and secondary surgery groups (97.0 vs 98.5%, P= .194). Further analyses of RFS rates according to nodal stages and number of high-risk histologic features showed no difference between groups. Moreover, RFS rates were not different between the groups after PS matching. In multivariable Cox proportional regression analysis, baseline serum carcinoembryonic antigen level was an independent risk factor for cancer recurrence (hazard ratio, 1.464; 95% confidence interval, 1.242-1.725; P< .001) but prior endoscopic resection of T1 CRC was not (P= .201). Both PS analyses consistently showed no increase in cancer recurrence risk in the secondary surgery group. Our data showed no additional cancer recurrence risk by endoscopic resection before surgery of T1 CRC with high-risk histologic features.

Abstract PS1-14: Impact of axillary dissection and patterns of care in patients with ypN1 triple negative breast cancer receiving regional nodal irradiation

Abstract Background: The benefit of axillary lymph node dissection (ALND) in patients with pN1 disease on sentinel lymph node biopsy (SLNB) following neoadjuvant chemotherapy for invasive breast cancer in patients receiving regional nodal irradiation (RNI) is unclear, even in patients with high risk histologic features such as triple negative disease. We sought to determine any association of ALND with improved survival, as well as patterns of care in this cohort using the National Cancer Database (NCDB). Methods: The NCDB was queried for women ages 18-75 with cT1-3N1 and ypT0-T3N1M0 breast cancer that underwent definitive surgical resection with axillary staging followed by adjuvant regional nodal irradiation, with triple negative receptor status. Only patients who were treated from 2012 - 2015 were included for appropriate coding of the extent of axillary surgery. Overall survival was estimated using the Kaplan-Meier method and Cox proportional hazards models. An analysis of the number of lymph nodes removed, rate of RNI utilization, and rate of ALND was performed using the Wilcoxon rank-sum test, proportions of RNI utilization compared using the Chi-squared test, and correlation of these to year of diagnosis was evaluated with the Pearson correlation coefficient. Results: A total of 572 women were identified that met inclusion criteria. The median age was 53 (range 24-75) years. 67 (11.7%) of women had SLNB alone and 505 (88.3%) had ALND with or without SLNB. Four year OS was 66.7% in patients undergoing ALND compared to 70.6% in those that had SLNB alone (p = 0.47). Charlson-Deyo comorbidity index (CDCC) (p = 0.01) and clinical T3 stage (p = 0.03) were significantly associated with survival. After adjusting for age, histology, clinical and pathologic T-stage, and CDCC, there was no significant relationship between receipt of ALND and overall survival (OS), however CDCC (p = 0.01) and cT3 or pT3 (p = 0.02 and p =0.01) remained significantly associated with OS. The mean number of lymph nodes sampled from 2012 to 2015 increased from 11.68 to 13.46 (p = 0.07). The rate of RNI increased from 55.6% in 2012 of patients to 58.4% in 2015 (p = 0.6). The rate of ALND increased from 83.9% in 2012 to 90.8% in 2015 (p = 0.2). Pearson correlation coefficients between mean number of lymph nodes sampled, rate of RNI, and rate of ALND were 0.83. 0.13, and 0.95 respectively. Conclusions: There was no difference in overall survival between patients with cT1-3N1M0 and ypT0-3N1M0 triple negative breast cancer receiving SLNB compared to ALND with adjuvant RNI, even when adjusting for tumor size and comorbidities, which remained significant risk factors. There was a trend towards an increase in the mean number of lymph nodes sampled and increased utilization of ALND, though these failed to reach statistical significance. We await the results of the Alliance 011202 randomized trial to provide prospective guidance of the utility of ALND in this high risk subgroup. Table 1. Baseline Characteristics For Triple-Negative PatientsSLNB (n=67)ALND (n=505)Median Age (Years)5353Histology (n, %)Ductal61 (91%)452 (90%)Lobular2 (3%)15 (3%)Other4 (6%)38 (7%)T-Stage (n,%)cT111 (16%)73 (15%)cT234 (51%)290 (57%)cT322 (33%)142 (28%)CDCC (n,%)054 (81%)441 (87%)19 (13%)51 (10%)24 (6%)8 (2%)30 (0%)5 (1%)Mean CDCC0.250.16Facility Type (n,%)Community5 (7%)36 (7%)Comprehensive Community27 (40%)171 (34%)Academic/Research13 (19%)160 (32%)Integrated Network13 (19%)72 (14%)Other/Unknown9 (14%)66 (13%)Lymphovascular Invasion (%)32.84%32.48%Median Tumor Size (cm)3.63.3Median Nodes Examined412Median Nodes Positive12 Citation Format: Michael Kharouta, Nicholas Damico, Megan Miller, Eleanor Harris, Janice Lyons. Impact of axillary dissection and patterns of care in patients with ypN1 triple negative breast cancer receiving regional nodal irradiation [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 PS1-14.