Bilobar Liver Metastases Research Articles

Contrast-enhanced intraoperative ultrasound improved hepatic recurrence-free survival in initially unresectable colorectal cancer liver metastases

BackgroundWe aimed to evaluate the role of Contrast-enhanced intraoperative ultrasound (CE-IOUS) with perfluorobutane microbubbles (Sonazoid) in improving the prognosis of patients with unresectable colorectal cancer liver metastases (CRLM). MethodsA total of 130 Patients with unresectable CRLM who underwent curative hepatic resection at our institute were retrospectively analyzed. Of these 130 enrolled patients, 67 underwent intraoperative ultrasound alone (IOUS group); 63 underwent additional CE-IOUS and IOUS (CE-IOUS group). Normalized inverse probability treatment weighting (IPTW) was employed to balance baseline characteristics between groups. Hepatic recurrence-free survival (HRFS) and overall survival (OS) were compared. ResultsThe treatment strategy was altered in 25 patients (25/63, 39.9%) due to the additional use of CE-IOUS. After applying IPTW, the CE-IOUS group exhibited a significantly lower rate of hepatic recurrence (hazard ratio [HR], 0.55; 95% confidence interval [CI] 0.32–0.95; P = 0.032). Subgroup analysis showed that CE-IOUS provided a significant benefit over IOUS in patients with bilobar liver metastases (P = 0.007), or with a number of live tumors < 3 (P = 0.021), or without DLM (P = 0.018), or with extrahepatic metastasis (P = 0.034), or with a minimum of 6 cycles of systemic therapy (P = 0.03). ConclusionsCE-IOUS is necessary for unresectable CRLM after preoperative chemotherapy, as it enhances detection accuracy and improves the prognosis of unresectable CRLM patients.

Liver Resection in Synchronous Bilobar versus Unilobar Colorectal Liver Metastases: A Retrospective Analysis of Oncological Outcomes and Patient Survival

Introduction: Resection of colorectal liver metastasis has emerged as the standard treatment. Our study compares oncological outcomes of patients with resected synchronous bilobar versus unilobar colorectal liver metastasis. Methods: This retrospective study presents long-term follow-up data of 105 consecutive patients with primary colorectal cancer and synchronous liver metastasis. All patients underwent primary tumor and metastasis resections between 2007 and 2019. Results: Fifty-five patients with bilobar and 50 patients with unilobar colorectal liver metastases were included. No significant difference in overall, tumor-specific, or recurrence-free survival was observed between patients with bilobar and unilobar metastases. After case-control matching, the results were confirmed in patients with similar tumor burdens. In the multivariate analysis, chemotherapy following liver metastasis resection was a significant prognostic factor associated with improved overall survival (hazard ratio 0.518, 95% confidence interval: 0.302–0.888, p = 0.017). Conclusion: Overall survival, as well as tumor-specific and recurrence-free survival, did not differ between patients with unilobar and bilobar liver metastasis. These findings contribute to the understanding that primary tumor and metastasis resection in eligible patients improve long-term outcomes.

Minimally invasive approach for synchronous resection of small bowel endocrine tumour with bilobar LIVER metastases (WITH VIDEO)

Minimally invasive approach for synchronous resection of small bowel endocrine tumour with bilobar LIVER metastases (WITH VIDEO)

Intra-arterial peptide-receptor radionuclide therapy for neuro-endocrine tumour liver metastases: an in-patient randomised controlled trial (LUTIA)

PurposePeptide receptor radionuclide therapy (PRRT) using [177Lu]Lu-DOTATATE has been shown to effectively prolong progression free survival in grade 1–2 gastroenteropancreatic neuroendocrine tumours (GEP-NET), but is less efficacious in patients with extensive liver metastases. The aim was to investigate whether tumour uptake in liver metastases can be enhanced by intra-arterial administration of [177Lu]Lu-DOTATATE into the hepatic artery, in order to improve tumour response without increasing toxicity.MethodsTwenty-seven patients with grade 1–2 GEP-NET, and bi-lobar liver metastases were randomized to receive intra-arterial PRRT in the left or right liver lobe for four consecutive cycles. The contralateral liver lobe and extrahepatic disease were treated via a “second-pass” effect and the contralateral lobe was used as the control lobe. Up to three metastases (> 3 cm) per liver lobe were identified as target lesions at baseline on contrast-enhanced CT. The primary endpoint was the tumour-to-non-tumour (T/N) uptake ratio on the 24 h post-treatment [177Lu]Lu-SPECT/CT after the first cycle. This was calculated for each target lesion in both lobes using the mean uptake. T/N ratios in both lobes were compared using paired-samples t-test.FindingsAfter the first cycle, a non-significant difference in T/N uptake ratio was observed: T/NIA = 17·4 vs. T/Ncontrol = 16·2 (p = 0·299). The mean increase in T/N was 17% (1·17; 95% CI [1·00; 1·37]). Of all patients, 67% (18/27) showed any increase in T/N ratio after the first cycle.ConclusionIntra-arterial [177Lu]Lu-DOTATATE is safe, but does not lead to a clinically significant increase in tumour uptake.

Indocyanine Green Fluorescence for Liver Assessment and Imaging-Guided Resection of Colorectal Metastases: A Case Report

Abstract Introduction Liver resection is widely accepted as a treatment option for primary liver cancer and metastases. The goal of surgery is to resect all tumours with negative histological margins while preserving sufficient functional hepatic parenchyma and reducing postoperative complications. The use of Indocyanine green (ICG) for liver function assessment and fluorescence image-guided surgery could be used to achieve that goal. Clinical Case Description We present the case of a 62-year-old female patient with diagnosed sigmoid colon cancer with four bilobar liver metastases who underwent a simultaneous sigmoid resection and ICG fluorescence image-guided liver resection 3 days after preoperative ICG liver function assessment. We decided to perform liver-sparing resection having in mind the liver metastases’ number, size and location and the slightly impaired liver function (ICG retention rate 15 – ICGR15 was 14,02%). All liver tumours were removed without complications, and the resected margins were all microscopically free of tumour tissue (R0 resection). The postoperative period was uneventful, without any signs of postoperative liver failure. Conclusions ICGR15 can be considered a safe and informative marker for liver function and indirectly for the degree of portal hypertension. ICG fluorescence provides an additional method to assist intra-operative tumour identification. The best timing of injection requires further study.

Assessing the Impact of Primary Tumour Location on Survival After Resection of Colorectal Liver Metastases: A Propensity Weighted Retrospective Cohort Study.

Right-sided colonic tumours appear to have poorer survival after resection of colorectal liver metastases, although this may be confounded by various factors including advanced stage and emergency presentation. Medical records of consecutive patients undergoing resection of colorectal liver metastases at a single centre from 2008 to 2015 were retrospectively reviewed. Cases were categorised by primary tumour location (right colon, left colon, rectum). Each primary location was weighted using propensity scores to balance covariates, including staging and mode of presentation. Cox regression was then applied to derive multivariable hazard ratios (HR) of survival after liver resection. Primary outcomes were 10-year overall survival (OS) and 5-year disease-free survival (DFS) after liver resection based on PTL. 414 patients were included in the analysis. Left colonic tumours were significantly associated with higher rates of bilobar liver metastasis (36.2% vs. 20.1% and 30.1%) and larger maximum size of liver metastases compared with rectal and right-sided tumours, respectively. There was no difference in rates of extra-hepatic metastases, recurrence in the liver after resection or RAS, BRAF or p53 mutational status. After propensity weighting and Cox-regression, right-sided tumours were independently associated with significantly reduced 10year OS (HR 1.56, 95% CI 1.03-2.36, p = 0.04) but not 5year DFS (HR 1.36, 95% CI 0.89-2.08, p = 0.15). Compared with left colonic and rectal tumours, right-sided colonic tumours are independently associated with inferior OS after resection of CRLM. This is despite higher rates of bilobar liver metastases and larger metastases with left-sided tumours.

Parenchymal sparing surgery experience in colorectal cancer patients with bilobar liver metastases

Background: The debate over the surgical strategy optimization in colorectal cancer patients with liver metastases (mCRC) has been ongoing in the last 20 years. However, parenchyma sparing surgery (PPS) in cases of hard to reach liver cites (HTRLC) remain to be controversial.

No.253 Lymph Nodes Metastasis in Left-Sided Colorectal Cancer Liver Metastasis (CRLM) Patients: Incidence and Prognosis.

Background:No.253 lymph node is the gateway to systemic metastasis for left-sided colorectal cancer. However, the value of D3 resection is still controversial. This study aimed to identify the incidence rate and prognostic value of 253LN metastasis in patients with left-sided colorectal cancer liver metastasis (CRLM) mainly through blood vessels and thus to provide theoretical basis for 253LN resection.Methods:From February 2012 to February 2019, a total of 281 patients who underwent curative resection for both primary and metastatic tumors were collected retrospectively. The clinicopathological and genetic characteristics were compared between 58 patients with positive 253LN and 223 patients with negative. Relapse-free survival (RFS) and overall survival (OS) were compared with Kaplan–Meier method. Cox regression analysis and a forest plot were conducted for RFS.Results:The incidence of 253LN metastasis in left-sided CRLM was 20.64% (58/281). Those with 253LN positive were T4 stage, N2 stage, and D1/D2 lymph nodes metastatic. About 10.3% (8/78) 253LN positive patients were D1/D2 negative. The 253LN metastasis was an independent risk factor for relapse after curative surgery, but not for OS. Patients with 253LN metastasis had worse RFS, especially in female, adenocarcinoma, poorly differentiated, pT3, preoperative serum CA199 < 37 U/mL, bilobar liver metastasis, without preoperative chemotherapy, KRAS, NRAS, or BRAF wild type.Conclusion:The incidence of 253LN metastasis in left-sided CRLM is 20.64%, and skip metastasis rate is 10.3%. The 253LN status is an independent prognostic risk factor for RFS but not for OS after curative surgery. Routine resection of 253LN should be applied in curative surgery of left-sided CRLM.

Laparoscopic Parenchymal Sparing Multiple Metastatectomy Combined with Left Lateral Segmentectomy for Long Term Hepatic Recurrence from Resected Solid Pseudopapillary Tumor of Pancreas

Introduction: Solid pseudopapillary neoplasm(SPN) of the pancreas are rare tumors that occurs in young women. SPN can metastasizes in 5–15% of all cases and the common site is the liver. The management of metastatic tumors of SPN is unclear. We report a case of Laparoscopic Parenchymal Sparing Multiple Metastatectomy Combined with Left Lateral Segmentectomy for long term Hepatic Recurrence from Resected Solid Pseudopapillary tumor of Pancreas. Case/methods: A 26-year-old lady underwent distal pancreatectomy with splenectomy on 30/3/2015 for solid pseudopapillary tumor of pancreas. Patient was on routine follow up and a PET CT done on 14/10/2020 showed Multiple Bilobar Liver Metastasis in Segments 2/3, 6, 7, 8. Patient underwent of Laparoscopic Parenchymal Sparing Multiple Metastatectomy Combined with Left Lateral Segmentectomy on 22/10/2020. Intra operatively, metastasis was noted at segment 6,7,8 sub capsular. Intraoperative USG showed deep seated segment 2 metastasis for which Laparoscopic left lateral Segmentectomy was done. Results: Postoperative period was uneventful. Histopathology confirmed the 4 metastasis with adequate margins. She was discharged on post-operative day 2. Post 10 months of surgery patient is having a disease-free survival. Conclusion: Long term hepatic recurrence in SPN is rare. Aggressive management of Liver Metastasis ensures a long term disease free survival. In our case we were able to manage the multiple liver metastasis using a combination of Laparoscopic Parenchymal sparing hepatic metastatectomy and Left Lateral Segmentectomy to achieve a R0 resection and this reinforces the role of laparoscopic liver surgery even in such rare tumors.

Two stage hepatectomy (TSH) or Associating liver partition and portal vein ligation for staged hepatectomy (ALLPS) for bilobar multiple colorectal liver metastasis

Of patients with colorectal cancer, 30% to 50% present with liver metastasis at the time of diagnosis or develop metastasis later. Hepatectomy is the primary curative treatment option for patients with colorectal liver metastases (CRLMs). Patients with bilateral, multiple CRLMs and a small estimated tumor free future liver remnant (FLR) present a treatment challenge. These patients may need a two-stage hepatectomy (TSH) in which portal venous ligation (PVL) or portal venous embolization (PVE) is included in the first stage to stimulate hypertrophy of the FLR before final resection. This method generates a 27% to 39% increase in FLR volume in 4 to 8 weeks. The risks in this method are tumor progression during the waiting period and insufficient hypertrophy, making resection impossible in 25% to 38% of the patients preparing to undergo TSH. To increase liver growth rate and volume, which renders more patients resectable in a shorter time, a novel concept of liver resection, associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), was described in 2011. However, in the early study 68% of the patients experienced complications and the surgical mortality rate was 12%. A recent, the only multicenter randomized controlled trial (RCT) revealed that compared with the use of TSH, the use of ALPPS for patients with CRLM resulted in a higher resection rate (92%) without a higher 90-day mortality rate (8.3%), a higher rate of severe complication rate (43%) or a lower rate of negative surgical margins in the liver. A previous meta-analysis including 9 retrospective studies showed that TSH for CRLM exhibited lower perioperative morbidity and mortality rates than ALPPS, suggesting the superiority of TSH. On the other hand, in a recent meta-analysis in 2020 including 7 retrospective studies and 1 RCT, compared with TSH, ALPPS for advanced CRLM resulted in superior surgical efficacy with comparable perioperative mortality rate and short-term oncological outcomes, while this was at the cost of increased perioperative minor complications. From a clinical perspective, traditional TSH has been frequently regarded as a preferred treatment modality in earlier studies, and ALPPS was reserved as an alternative, typically after failed PVE or PVL. At present, this paradigm may have changed, as there is growing evidence indicating that the surgical benefits given by ALPPS are at least not inferior to those given by TSH according to recent studies. ALPPS may be feasible for bilobar multiple colorectal liver metastasis. Still, long-term outcomes remain to be elucidated and therefore the role of ALPPS regarding oncological outcome remains uncertain.

Combined liver resection and radiofrequency ablation for bilobar multiple colorectal liver metastasis

Combined liver resection and radiofrequency ablation for bilobar multiple colorectal liver metastasis

Upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer with synchronous liver metastases

BackgroundThe optimal treatment of locally advanced rectal cancer with synchronous liver metastases remains controversial. In this study, we aimed to evaluate the safety, efficacy, and oncologic outcomes of upfront chemotherapy and short-course radiotherapy with delayed surgery in patients with locally advanced rectal cancer and synchronous liver metastases. MethodsForty-four patients who underwent upfront chemotherapy and short-course radiotherapy with delayed surgery for locally advanced rectal cancer (cT3/4, <2.0 mm from the mesorectal fascia) with synchronous liver metastases between January 2010 and June 2017 were reviewed retrospectively. Primary and metastatic liver lesions were resected with curative intent. Upfront chemotherapy and short-course radiotherapy were administered. Thereafter, restaging, surgery only, or additional chemotherapy followed by surgery was performed. ResultsAt the time of initial diagnosis, 20 patients had <3 liver metastases; 24 patients had ≥3 liver metastases. Twenty-three patients had hemi-liver metastases; 21 patients had bilobar liver metastases. R0 resection of rectal lesions was achieved in 43 patients. Synchronous R0 resection of liver metastases was achieved in 41 patients. Postoperative complications (Clavien–Dindo Grade ≥ III) were noted in 5 patients. Grade 3/4 adverse events were observed in 26 patients. All adverse events were managed effectively with medication and supportive care. The 3-year overall survival and progression-free survival rates were 65.3% and 26.9%, respectively. ConclusionUpfront chemotherapy and short-course radiotherapy with delayed surgery appear to be safe and effective in patients with locally advanced rectal cancer and synchronous liver metastases without substantially increasing treatment induced morbidity.

Abstract No. 184 Radioembolization for metastatic succinate dehydrogenase–deficient gastrointestinal stromal tumors

Succinate dehydrogenase (SDH)-deficient gastrointestinal stromal tumors (GIST) are a rare subset of GIST that mostly affect adolescents and young adults. SDH-deficient GISTs have the propensity to frequently metastasize to the liver. Because these tumors lack mutations in the proto-oncogene receptor tyrosine kinase, KIT and PDGFRA, they generally do not respond well to standard treatments for GIST. Surgical management is considered first-line treatment; however, due to the presence of often diffuse, bilobar liver metastases, hepatic resection is often not feasible.

Rate of Curative Surgery in Real-world Patients with Unresectable Metastatic Colorectal Cancer Treated with FOLFOXIRI ± Bevacizumab: A Western Canadian Province Experience.

Recent evidence from randomized trials suggests that FOLFOXIRI (fluorouracil, oxaliplatin, and irinotecan) ± bevacizumab is associated with higher response rates, with the potential for conversion of unresectable to resectable disease in metastatic colorectal cancer (mCRC). However, limited evidence is available on the efficacy and safety of this regimen in real-world patients with mCRC. The current study aims to evaluate the conversion rate and safety of FOLFOXIRI ± bevacizumab in real-world patients with unresectable mCRC. In this retrospective multicenter population-based cohort study, patients who were diagnosed with unresectable mCRC between January 2015 and December 2018 in Saskatchewan and received FOLFOXIRI ± bevacizumab were assessed. Kaplan-Meier survival methods and the log-rank test were performed. A total of 28 eligible patients with a median age of 51years (interquartile range 39-60) and a male:female ratio of 11:17 were identified; 39% had rectal cancer, 46% had extrahepatic disease, and 46% had bilobar liver metastases. Overall, 63% of the patients had a positive response to FOLFOXIRI ± bevacizumab and 53% underwent metastasectomy. Of all patients 60% had grade 3/4 toxicity and 32% required hospital admission. No treatment-related mortality was noted. After 4years, 50% of the patients were alive. Median progression-free survival of patients who underwent surgery was 18months (95% CI 11.3-24.7) versus 11months (4-18.1) without surgery (p=0.28). Median overall survival of patients with surgery was 33months (17.5-48.5) versus 16months (8.3-23.7) without surgery (p=0.03). The current study suggests that FOLFOXIRI ± bevacizumab therapy in real-world patients with mCRC is associated with a high rate of conversion from unresectable to resectable metastatic disease. Patients with metastasectomy had better survival.

A Case Report on a Pancreatic Enigma: Metastatic Solid Pseudopapillary Neoplasm

Introduction: Solid pseudopapillary neoplasm is a unique enigmatic disease typically affecting young females. Being a low-grade neoplasm surgical resection is often curative. Rare cases (5-15%) present with distant metastasis. Only 2% has lymph nodal metastasis. This is a case report of metastatic SPN with both visceral and lymph nodal involvement. The work has been reported in line with the SCARE criteria. Case Presentation: The authors present a case of metastatic SPN in an 18-year-old female who came with an abdominal lump. Contrast enhanced CT abdomen findings were in favour of huge SPN arising from pancreatic tail. The prime concern was the coexistence of bilobar liver metastasis predominantly involving right lobe. The complexity of surgical resection along with metastatectomy in a young female was herculean. This clinical dilemma was tackled with staged resection. Conclusion: Even in metastatic SPN a reasonable survival can be achieved by surgical debulking. We emphasize the importance of aggressive approach in operable metastatic SPN.

STUDY OF THE POSSIBILITIES OF PREOPERATIVE CHEMOTHERAPY IN MULTIPLE METASTASIS OF COLORECTAL CANCER IN THE LIVER

Preoperative chemotherapy (CT) in 35 patients with colorectal cancer (CRC) with liver metastases demonstrated a high frequency of objective effects - in 22 (62.9%) patients, stabilization was noted in 10 (28.6%) cases. With bilobar liver metastases and the use of oxaliplatin-containing regimens, partial regression was 62.9%. Side effects in most cases were clinically insignificant, no deaths were observed. The results obtained demonstrate the possibility of performing extended surgical operations in the majority of CRC patients with multiple liver metastases after preoperative CT.

Total tumour volume as a prognostic factor in patients with resectable colorectal cancer liver metastases.

BackgroundAlthough total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM.MethodThis was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three‐dimensional construction software; cut‐off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence‐free survival (RFS) were determined using multivariable and Kaplan–Meier analyses.ResultsSome 94 patients were included. TTV cut‐off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5‐year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection.ConclusionTTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.

Resection of Adrenocortical Carcinoma with Bilobar Liver Metastasis Following Neoadjuvant Therapy Using a Modified Mini-ALPPS Approach: A Case Report

Introduction: Adrenocortical carcinoma (ACC) is an aggressive tumor with high proportion of patients presenting with metastatic disease, most commonly in the liver. Prognosis in this population is extremely poor. Resection of the primary tumor and liver metastasis offers a survival benefit in well-selected patients. However, the extent of surgery is often significant and can limit the ability to accomplish a safe marginnegative resection. Presentation of case: A 35-year-old male presented with a large left ACC (15.2cm) and multiple bilobar liver metastases (1.5-12.5cm). He was treated with mitotane and chemotherapy / immunotherapy, with excellent response. Multidisciplinary discussion led to recommendations for a curative-intent approach with surgery. A staged approach was performed for the resection, using a modified Mini-ALPPS technique. A complete margin-negative resection of all disease was accomplished. The patient recovered well and remains free of disease 24-months following diagnosis. Discussion: This case highlights novel components of treatment for metastatic ACC and for hepatectomy for bilobar liver metastasis. The decisions to proceed to surgery for complete resection and to use a staged approach with a modified Mini-ALPPS technique were both critical components to render the patient disease-free. Appropriate expertise and multidisciplinary teamwork are essential for implementation of these approaches. Conclusion: Neoadjuvant chemotherapy for stage IV ACC can result in disease control and improved selection of candidates for curative-intent surgery. In the setting of bilobar liver disease and a large primary in place, a modified Mini-ALPPS approach provides a safe and feasible way to accomplish complete resection and improved survival.

Major hepatectomy decreased tumor growth in an experimental model of bilobar liver metastasis

Background/PurposeTwo-stage hepatectomy (TSH), is associated with a risk of drop-out due to tumoral progression following portal vein occlusion (PVO). We explored the impact of majorhepatectomy on tumor growth by objective radiological measures comparing to PVO and minor hepatectomy, using a model of bilobar colorectal liver metastasis (CLM). MethodsCLM were induced in 48 BDIX rats by injection of DHDK12-cells. 7 days after cells injection, animals were distributed into 4 groups of equal number (n = 12): portal vein ligation (PVL), sham laparotomy (sham), minor (30%Phx) and major (70%Phx) hepatectomy. MR imaging was used for in vivo analysis of tumor implantation, growth and volumes. ResultsAt POD10, tumour volumes were homogeneously distributed among the 4 groups. Lower TV were significantly observed after 70%Phx comparing to PVL at POD17 (0.63 ± 0.14cm3 vs 0.9 ± 0.16cm3, p = 0.008) and to the 3 others groups at POD24: 1.78 ± 0.38cm3 vs 3.2 ± 0.62cm3 (PVL, p = 0.019), 2.41 ± 0.74cm3 (Sham, p = 0.024) and 2.32 ± 0.59cm3 (30%PHx, p = 0.019). ConclusionWe confirmed in a reproducible model that contrary to PVO, a major hepatectomy decreases the growth of CLM in the remnant liver. This result leads to questioning the usual TSH and justifies exploring alternative strategies. The “major hepatectomy first-approach” should be an option to be evaluated.

Rate of conversion from unresectable to resectable metastatic colorectal cancer (mCRC) in real-world patients (RWP) treated with FOLFIXIRI ± bevacizumab: A population-based retrospective cohort study.

21 Background: Recent evidence from randomized trials suggests that FOLFOXIRI (5FU, oxaliplatin, and irinotecan) ± bevacizumab is associated with higher response rates with a potential for conversion of unresectable to resectable disease in mCRC. Yet limited evidence is available about efficacy and safety of this regimen in RWP with mCRC. The current study aims to evaluate conversion rate and safety of FOLFOXIRI ± bevacizumab in RWP with unresectable mCRC. Methods: Each year about 175 patients are diagnosed with mCRC in Saskatchewan. Patients who were diagnosed with unresectable mCRC between Jan 2015 to Dec 2018 and received FOLFOXIRI ±bevacizumab were assessed. Kaplan Meier survival methods and log rank test were performed. Logistic regression analysis was performed to assess factors correlate with conversion. Results: 28 eligible patients with median age of 51 yrs (IQR:39-60) and M:F of 11:16 were identified. 42% patients had a comorbid illness, and 43% had WHO performance status of 0. 39% had rectal cancer, 46% had extrahepatic disease and 46% had bilobar liver metastases. 58% patients had a positive response to therapy, 60% had grade 3/4 toxicity &amp; 32% required hospital admission. No treatment-related mortality was noted. 54% patients underwent metastasectomy (liver 73%, peritoneum and or ovaries 20%, lung 6%). 68% had primary tumor resection, 29% received rectal radiation, 21% had ablation and 18% had second surgery for recurrence. At 4 years 50% patients are alive. Median progression free survival of patients who underwent surgery is 18 (95%CI:11.3-24.7) vs. 11 months (4-18.1) without surgery (P = 0.28). Median overall survival of patients with surgery is 33 (17.5-48.5) vs. 16 months (8.3-23.7) without surgery (P = 0.03). Positive response to treatment is correlated with conversion (odd ratio 21.7, p = 0.002). Conclusions: In the real world setting younger patients with good performance status received FOLFIRINOX ± bevacizumab. Despite high rates of toxicity, more than half of patients were able to undergo surgery. A positive response to treatment significantly correlates with metastasectomy.