Benefit of primary tumor resection in stage IV colorectal cancer with unresectable metastasis: a multicenter retrospective study using a propensity score analysis

Primary Tumor Resection for Metastatic Colorectal, Gastric and Pancreatic Cancer Patients: In Search of Scientific Evidence to Inform Clinical Practice

The management of the primary tumor in metastatic colorectal, gastric and pancreatic cancer patients may be challenging. Indeed, primary tumor progression could be associated with severe symptoms, compromising the quality of life and the feasibility of effective systemic therapy, and might result in life-threatening complications. While retrospective series have suggested that surgery on the primary tumor may confer a survival advantage even in asymptomatic patients, randomized trials seem not to definitively support this hypothesis. We discuss the evidence for and against primary tumor resection for patients with metastatic gastrointestinal (colorectal, gastric and pancreatic) cancers treated with systemic therapies and put in context the pros and cons of the onco-surgical approach in the time of precision oncology. We also evaluate current ongoing trials on this topic, anticipating how these will influence both research and everyday practice.

Not All Kirsten Rat Sarcoma Viral Oncogene Homolog Mutations Predict Poor Survival in Patients With Unresectable Colorectal Liver Metastasis

Objective: To assess the characteristics of Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations and investigated whether all KRAS mutations predict poor prognosis in patients with unresectable colorectal liver metastasis (CRLM). Methods: Correlations between KRAS-mutation status and clinicopathological characteristics of 93 patients with unresectable CRLM at our institution between 2010 and 2018 were retrospectively analyzed. Kaplan–Meier and Cox proportional hazard models were used to evaluate the prognostic significance of KRAS mutations. Results:KRAS were primarily single-point mutations, identified in 41.9% of patients. There were no significant differences in clinicopathological characteristics between wild-type KRAS and mutant KRAS. Patients with mutant KRAS had significantly worse overall survival (OS) and progression-free survival (PFS) than those with wild-type KRAS. Moreover, patients with codon 12 mutations had worse OS and PFS than those with wild-type KRAS, whereas mutations in codon 13 were not associated with a worse prognosis. Among the 5 most common mutations in codons 12, G12V, and G12D were associated with worse OS, furthermore, G12C mutation seemed to associated with worse PFS than patients with wild-type KRAS. Conclusion:KRAS codon 12 mutations were predictive for a poor prognosis in patients with unresectable CRLM. G12D and G12V mutations were associated with worse OS, whereas G12C mutation seemed to be associated with decreased PFS.

Impact of Primary Tumor Resection on Mortality in Patients with Stage IV Colorectal Cancer with Unresectable Metastases: A Multicenter Retrospective Cohort Study

BACKGROUND

Primary tumor resection (PTR) before commencing systemic chemotherapy in patients with stage IV colorectal cancer and unresectable metastases (mCRC) remains controversial. This study aimed to assess whether PTR before systemic chemotherapy is associated with mortality in mCRC patients, after adjusting for confounding factors, such as the severity of the primary tumor and metastatic lesions.

METHODS

We analyzed hospital-based cancer registries from nine designated cancer hospitals in Fukushima Prefecture, Japan. Patients were divided into two groups (PTR and non-PTR), based on whether PTR was performed as initial therapy for mCRC or not. The primary outcome was all-cause mortality. Kaplan-Meier survival analysis was performed, and survival estimates were compared using the log-rank test. Adjusted hazard ratios were calculated using Cox regression to adjust for confounding factors. All tests were two-sided; P-values < 0.05 were considered statistically significant.

RESULTS

Between 2008 and 2015, 616 mCRC patients were included (PTR: 414 [67.2%]; non-PTR: 202 [32.8%]). The median follow-up time was 18.0 (interquartile range [IQR]: 8.4-29.7) months, and 492 patients (79.9%) died during the study period. Median overall survival in the PTR and non-PTR groups was 23.9 (IQR: 12.2-39.9) and 12.3 (IQR: 6.2-23.8) months, respectively (P < 0.001, log-rank test). PTR was significantly associated with improved overall survival (adjusted hazard ratio: 0.51; 95% confidence interval: 0.42-0.64, P < 0.001).

CONCLUSIONS

PTR before systemic chemotherapy in patients with mCRC was associated with improved survival.

Efficacy of Primary Tumor Resection in Metastatic Colorectal Cancer

BACKGROUND The aim of this study was to evaluate the survival benefit of palliative primary tumor resection in colorectal cancer (CRC) patients with unresectable metastases. MATERIAL AND METHODS Clinicopathological characteristics of eligible patients who underwent surgery to remove the primary tumor and those who did not between 2004 and 2013 were compared. We also evaluated the association between survival and different clinicopathologic characteristics in metastatic CRC. RESULTS The percentage of patients undergoing surgical resection of the primary tumor was higher during the earlier years and trended toward less use of surgery in later years. Palliative primary tumor resection was strongly associated with better cause-specific survival (hazard ratio=0.403, 95% confidence interval=0.389 to 0.417, P<0.001). CONCLUSIONS We added new strong evidence supporting the survival benefit of palliative resection, which should be confirmed in future randomized controlled trials.

Efficacy of surgery and chemotherapy for stage IV small bowel adenocarcinoma: A population-based analysis using Surveillance, Epidemiology, and End Result Program database

BACKGROUND

The role of surgery and chemotherapy for stage IV small bowel adenocarcinoma (SBA) is still confused. The results from previous analyses have been limited by small sample sizes and different treatment regimens.

METHODS

Patients with stage IV SBA were identified in the Surveillance, Epidemiology, and End Result Program (SEER) database. Cause-specific survival (CSS) and overall survival (OS) were calculated with Kaplan-Meier methods and log-rank test. Multiple logistic and Cox regression identified covariates associated with treatment options and survival.

RESULTS

1219 eligible patients were involved in this study. The median age was 67 (range, 20-95) with 655 (53.7%) males and 564 (46.3%) females. Age and primary tumor site were significantly associated with surgery performance, age was also significantly associated with chemotherapy (P < .01). To reduce bias, further six subgroups were divided by age (≤65 and >65) and primary tumor site (duodenum, jejunum and ileum). Chemotherapy and surgery conferred a benefit on survival of the whole cohort (the median CSS of different treatment groups were 17, 9, 4, and 1 month respectively, P < .001) and most subgroups (83.3%, 5/6). In multivariate analysis, surgery (P = .006), and chemotherapy (P = .038) are still independent factors of favorable CSS and OS. For patients with surgery (n = 362), radical surgery was not associated with better survival.

CONCLUSION

For stage IV SBA patients, the present study showed that age and primary tumor site were significantly associated with treatment preference. Surgery and chemotherapy were consistently correlated with favorable survival for the whole cohort or most specific subgroups. However, compared with palliative surgery, significant association was not found in patients with radical surgery with better outcome. More prospective well-defined cohorts would add knowledge for this rare disease.

Bevacizumab improves survival in metastatic colorectal cancer patients with primary tumor resection: A meta-analysis

It is not well determined whether primary tumor resection is associated with better outcomes in metastatic colorectal cancer (mCRC) patients treated with bevacizumab. In this meta-analysis, we aimed to assess the prognostic role of primary tumor resection in mCRC treated with bevacizumab. Electronic databases including the Cochrane library, Embase, and Pubmed were searched until April 2018. Clinical studies assessing the influence of primary tumor resection on the efficacy of bevacizumab in patients with mCRC were identified. The primary endpoint was overall survival (OS), and the secondary endpoint was progression-free survival (PFS). Seven studies including 2760 mCRC patients were finally included. The results of the meta-analysis were in favor of bevacizumab to patients with resected primary tumor in terms of OS (HR = 0.50, 95%CI: 0.39–0.64; p < 0.01), and PFS (HR = 0.65, 95%CI: 0.51–0.81; p < 0.01). Administration of bevacizumab in mCRC patients with resected primary tumor had a better OS (HR = 0.65, 95%CI: 0.56–0.74; p < 0.01), when compared to chemotherapy(CT). Adding bevacizumab to mCRC patients without resection of primary tumor also had a better OS (HR = 0.78, 95%CI: 0.65–0.94; p < 0.01) and PFS (HR = 0.71, 95%CI: 0.57–0.88; p < 0.01) compared to chemotherapy alone. In conclusion, mCRC patients with resected primary tumor have better survival than those without surgery of primary tumor when treated with bevacizumab. Primary tumor resection status should be taken into consideration when using bevacizumab in mCRC.

National statistics about resection of the primary tumor in asymptomatic patients with Stage IV colorectal cancer and unresectable metastases. Need for improvement in data collection. A systematic review with meta-analysis

BACKGROUND

Patients with asymptomatic Stage IV colorectal cancer represent a significant heterogeneous group. National statistics represent an effective method to follow in real time the clinical outcomes of patients, and they may represent an important tool to analyze and to compare different therapeutic approaches. The aim of our study was to analyze the reviews of national data and single institutions reports, which compared the clinical outcomes of patients with asymptomatic Stage IV colorectal cancer and un-resectable metastases who had resection of the primary tumor with those who did not have resection. We gave special attention to the number of missing established relevant variables, to determine the appropriateness of the results of the published studies.

MATERIAL

We performed a systematic review of papers comparing patients who had and who had not primary tumor resection. Screened reports included the time of publication from June 2012 to June 2018; 2556 papers were identified and 27 were included into the review. The primary outcome was observed survival. We analyzed the number of major missing variables in National Data Bases and Single Institution Reports, to assess the overall validity of the conclusions of the analyzed reports.

RESULTS

In the majority of the reports and in the meta-analysis of studies with propensity score matching, resection of the primary tumor was correlated to improved survival and to the possibility for a better response to postoperative chemotherapy.

CONCLUSIONS

The high number of missing significant variables, and a clear clinical selection in single center reports make any analysis error-prone. National statistics might represent a valid method to follow in real time the clinical outcomes of these patients, comparing different therapeutic approaches. There is the need for improvement in national data collection, to make descriptive national statistics the ground for future progress in treatment. (PROSPERO) CRD 42018089691.

A systematic analysis highlighting deficiencies in reported outcomes for patients with stage IV colorectal cancer undergoing palliative resection of the primary tumour

BACKGROUND

Management of the primary tumour in the presence of unresectable metastatic colorectal cancer (mCRC) is controversial. The role of primary tumour resection (PTR) has been investigated by a number of retrospective cohort studies, with a number on going randomised controlled trials. The aim of this study was to identify the clinical and patient-reported outcomes currently reported in studies that evaluate the role of PTR in mCRC.

METHODS

Literature searches were performed in MEDLINE (via OvidSP) (1966-June 2017), EMBASE (via OvidSP) and the Cochrane Library using terms related to colorectal cancer and primary tumour resection. All studies documenting outcomes following palliative PTR were included. Eligible articles were assessed using the Risk of Bias In Non-Randomised Studies of Intervention (ROBINS-I) tool.

RESULTS

Of 11,209 studies screened, 59 non-randomised studies reporting outcomes on 331,157 patients were included. Patient characteristics regarding performance status and co-morbidity were recorded in 26 (44.1%) and 17 (28.8%) studies. The chemotherapy regime used was reported in 27 (45.8%) studies. The operative setting and the operative approach was reported in 42 (71%) and 14 (23.7%) studies. Post-operative mortality and morbidity were reported in 33 (55.9%) and 35 (59.3%) studies. Overall survival was reported in 49 (83.1%) studies, with 5 different definitions identified. Quality of life was only reported in 1 (1.7%) study.

CONCLUSION

This study demonstrates significant heterogeneity in the selection and definition of outcomes reported following PTR in mCRC. There is significant heterogeneity with a significant under-reporting of important outcomes such as treatment related adverse events and patient reported outcomes.

Meta-analysis of outcomes following resection of the primary tumour in patients presenting with metastatic colorectal cancer

BACKGROUND

It is not clear whether resection of the primary tumour (when there are metastases) alters survival and/or whether resection is associated with increased morbidity. This systematic review and meta-analysis assessed the prognostic value of primary tumour resection in patients presenting with metastatic colorectal cancer.

METHODS

A systematic review of MEDLINE/PubMed was performed on 12 March 2016, with no language or date restrictions, for studies comparing primary tumour resection versus conservative treatment without primary tumour resection for metastatic colorectal cancer. The quality of the studies was assessed using the MINORS and STROBE criteria. Differences in survival, morbidity and mortality between groups were estimated using random-effects meta-analysis.

RESULTS

Of 37 412 initially screened articles, 56 retrospective studies with 148 151 patients met the inclusion criteria. Primary tumour resection led to an improvement in overall survival of 7·76 (95 per cent c.i. 5·96 to 9·56) months (risk ratio (RR) for overall survival 0·50, 95 per cent c.i. 0·47 to 0·53), but did not significantly reduce the risk of obstruction (RR 0·50, 95 per cent c.i. 0·16 to 1·53) or bleeding (RR 1·19, 0·48 to 2·97). Neither was the morbidity risk altered (RR 1·14, 0·77 to 1·68). Heterogeneity between the studies was high, with a calculated I² of more than 50 per cent for most outcomes.

CONCLUSION

Primary tumour resection may provide a modest survival advantage in patients presenting with metastatic colorectal cancer.

A phase II study of 5-fluorouracil/L-leucovorin/oxaliplatin (mFOLFOX6) in Japanese patients with metastatic or unresectable small bowel adenocarcinoma

BACKGROUND

Several studies have suggested that chemotherapy prolonged survival in patients with metastatic or recurrent small bowel adenocarcinoma (SBA); however, there is still no standard chemotherapy regimen. Here, we evaluated the efficacy and safety of a 5-fluorouracil (5-FU)/L-leucovorin (l-LV)/oxaliplatin (mFOLFOX6) protocol as a first-line therapy for patients with SBA.

PATIENTS AND METHODS

This was a multicenter, single-arm, open-label phase II study. Eligibility criteria included histologically confirmed adenocarcinoma, age 20-80 years, and an Eastern Cooperative Oncology Group performance status (PS) of 0-2. The primary endpoint was 1-year progression-free survival (PFS). The secondary endpoints included overall response rate (ORR), overall survival (OS), overall PFS, and safety.

RESULTS

Between April 2010 and November 2012, 24 patients were enrolled from 12 institutions. The median age of the patients was 63 years (range 31-79) and there was a male/female ratio of 18/6. The number of PS 0/1 patients was 17/7 and locally advanced/metastatic disease was seen in 2/22 patients, respectively. The primary tumor site was the duodenum in 14 patients (58%) and jejunum in 10 patients (42%). The median follow-up time was 14.7 months (3.7-40.3). The 1-year PFS was 23.3%. The ORR was 9/20 (45%). The median PFS and OS times were 5.9 months (95% confidence interval [CI] 3.0-10.2) and 17.3 months (95% CI 11.7-19.0), respectively. Major grade 3/4 toxicities were neutropenia (38%), anemia/peripheral neuropathy (25%), and stenosis (17%). There were no treatment-related deaths.

CONCLUSIONS

Although the primary endpoint was not met, mFOLFOX6 showed effective and good tolerance as a first-line treatment for SBA.

Asymptomatic primary tumour in incurable metastatic colorectal cancer: is there a role for surgical resection prior to systematic therapy or not?

INTRODUCTION

The role of the resection of asymptomatic primary colorectal cancer in patients with incurable disease is questionable.

AIM

To evaluate the impact of the resection of asymptomatic primary tumour on overall survival in patients with unresectable distant metastases.

MATERIAL AND METHODS

Patients treated in the National Cancer Institute, Lithuania, in the period 2008-2012, were selected retrospectively. The main inclusion criteria were: metastatic colorectal cancer (mCRC), endoscopically and histologically confirmed adenocarcinoma, without any symptoms for urgent operation, and at least one cycle of palliative chemotherapy administered. Information on patients' age, gender, tumour histology, localization of the tumour, regional lymph node involvement, number of metastatic sites, surgery and systemic treatment was collected prospectively. Eligible patients for the study were divided into two groups according to the initial treatment - surgery (patients who underwent primary tumour resection) and chemotherapy (patients who received chemotherapy without surgery). The impact of initial treatment strategy, tumour size and site, regional lymph nodes, grade of differentiation of adenocarcinoma and application of biotherapy on overall cumulative survival was estimated using the Kaplan-Meier method. To compare survival between groups the log-rank test was used. Cox regression analysis was employed to assess the effects of variables on patient survival.

RESULTS

The study group consisted of 183 patients: 103 men and 80 women. The median age was 66 years (range: 37-91). There were no notable imbalances with regard to age, gender, number of metastatic sites, metastases (such as pulmonary, peritoneal, liver, metastases into non-regional lymph nodes and other metastases), the number of received cycles of chemotherapy, first line chemotherapy type or biological therapy. Only 27 (14.8%) patients received biological therapy and the majority of them (n = 25, 92.6%) were treated with bevacizumab. For surgically treated patients 1-year survival was 71.2% (95% CI: 62.1-78.5) and 5-year survival was 4.0% (95% CI: 1.0-10.5). In the chemotherapy group, survival rates were lower - 43.9% (95% CI: 31.4-55.7) and 1.7% (95% CI: 0.1-8.1), respectively. Better survival rates were in the palliative surgery group. Multivariate analysis using the Cox proportional hazards model revealed that the initial palliative surgery and the application of biological therapy were statistically significant independent prognostic factors for survival.

CONCLUSIONS

Our findings suggest that palliative resectional surgery for the primary tumour in patients with incurable mCRC improves survival. Of course, one can argue that patients in the surgery group were "less problematic". Prospective randomized trials are needed to delineate precisely the role of palliative surgery of the primary tumour in these patients.

Prognostic impact of lymph node dissection is different for male and female colon cancer patients: a propensity score analysis in a multicenter retrospective study

PURPOSE

Colon cancers in male and female patients are suggested to be oncologically different. The aim of this study is to elucidate the prognostic impact of lymph node dissection (LND) in male and female colon cancer patients.

METHODS

A total of 5941 stage I-III colon cancer patients who were curatively operated on during the period from 1997 to 2007 were retrospectively studied. Cancer-specific survival (CSS) was individually compared between for male and female patients treated with D3, D2, and D1 LND. Background differences of the patients were matched using propensity scores.

RESULTS

D3, D2, and D1 LND were performed in 3756 (63 %), 1707 (29 %), and 478 (8 %), respectively, and more extensive LND was indicated for younger patients and more advanced disease. D2 LND was significantly associated with decreased cancer-specific mortality compared to D1 LND in male patients (HR 0.54, 95 % CI 0.32-0.89, p = 0.04), but not in female patients. D3 LND did not correlate to an improved prognosis compared to D2 LND both in male and female patients.

CONCLUSIONS

D2 LND was associated with an improved CSS in male, but not female colon cancer patients, compared to D1 LND. This suggested that colon cancer in male and female patients might be oncologically different, and that the prognostic impact of the extent of surgical intervention for colon cancer might therefore be different between sexes.

Bevacizumab Efficacy Is Influenced by Primary Tumor Resection in First-Line Treatment of Metastatic Colorectal Cancer in a Retrospective Multicenter Study

INTRODUCTION

There is no predictive factor of response to bevacizumab in metastatic colorectal cancer. Nevertheless, preclinical studies demonstrated an interaction between primary tumor and metastatic sites for the neoangiogenesis regulation. The primary objective of our study was to identify an effect of up-front primary tumor resection (UPTR) on bevacizumab efficacy.

PATIENTS AND METHODS

Between 2008 and 2010, we retrospectively analyzed progression-free survival (PFS) and overall survival (OS) of 316 patients with synchronous and metachronous metastatic colorectal cancer according to bevacizumab addition to first-line chemotherapy and UPTR.

RESULTS

Among 206 patients with UPTR, the addition of bevacizumab to chemotherapy significantly improved OS compared to chemotherapy alone (29.8 vs. 23.9 months respectively; hazard ratio [HR] 0.58; 95% confidence interval [CI], 0.40-0.83; P = .003). This effect was confirmed in multivariate analysis. There was also a nonsignificant trend toward improved PFS (9.7 vs. 8.4 months respectively; HR 0.71; 95% CI, 0.50-1.02; P = .062). Conversely, among 110 patients without UPTR, the addition of bevacizumab to chemotherapy had no effect on OS compared to chemotherapy alone (18.2 vs. 19.3 months respectively; HR 0.96; 95% CI, 0.65-1.42; P = .853). Bevacizumab significantly improved PFS (8.1 vs. 5.7 months respectively; HR 0.66; 95% CI, 0.45-0.96; P = .032) without confirmation in multivariate analysis.

CONCLUSION

In this retrospective study, bevacizumab seems to improve OS only in patients with UPTR, which could suggest a complementarity of both therapeutic modalities for antiangiogenic effect.

Management of asymptomatic primary tumours in stage IV colorectal cancer: Review of outcomes

AIM: To compare outcomes for patients presenting with stage IV colorectal cancer and an asymptomatic primary tumour, undergoing primary tumour resection (PTR) plus palliative chemotherapy vs primary chemotherapy up-front.

METHODS: A literature search was conducted using MEDLINE and EMBASE. The primary outcome was overall survival. Secondary outcomes included perioperative mortality, morbidity and delayed surgical intervention rates in patients undergoing PTR and subsequent complication rates in patients with an un-resected primary tumour. Tertiary outcomes included impact on systemic treatment and identification of prognostic factors relevant for survival in this cohort.

RESULTS: Twenty non-randomised studies met the inclusion criteria. Eleven studies included comparative overall survival data. Three studies showed an overall survival advantage for PTR, 7 studies showed no statistically significant advantage, and 1 study showed a significant worsening in survival in the surgical group. The perioperative mortality rate ranged from 0% to 8.5%, and post-operative morbidity rate from 10% to 35%, mainly minor complications that did not preclude subsequent chemotherapy. The rate of delayed primary-tumour related symptoms, most commonly obstruction, in patients with an un-resected primary tumour ranged from 3% to 46%. The strongest independent poor prognostic factor was extensive hepatic metastases, in addition to poor performance status, M1b stage and non-use of modern chemotherapy agents.

CONCLUSION: Based on the current literature, both PTR and up front chemotherapy appear appropriate initial management strategies, with a trend towards an overall survival advantage with PTR. The procedure has a low post-operative mortality, and most complications are transient and minor. The results of recruiting randomised trials are eagerly anticipated.