Survival benefit in patients after palliative resection vs non-resection colon cancer surgery

A Machine Learning Approach Using FDG PET-Based Radiomics for Prediction of Tumor Mutational Burden and Prognosis in Stage IV Colorectal Cancer

INTRODUCTION

We assessed the performance of F-18 fluorodeoxyglucose positron emission tomography (FDG PET)-based radiomics for the prediction of tumor mutational burden (TMB) and prognosis using a machine learning (ML) approach in patients with stage IV colorectal cancer (CRC).

METHODS

Ninety-one CRC patients who underwent pretreatment FDG PET/computed tomography (CT) and palliative chemotherapy were retrospectively included. PET-based radiomics were extracted from the primary tumor on PET imaging using the software LIFEx. For feature selection, PET-based radiomics associated with TMB were selected by logistic regression analysis. The performances of seven ML algorithms to predict high TMB were compared by the area under the receiver's operating characteristic curves (AUCs) and validated by five-fold cross-validation. A PET radiomic score was calculated by averaging the z-score of each radiomic feature. The prognostic power of the PET radiomic score was assessed using Cox proportional hazards regression analysis.

RESULTS

Ten significant radiomic features associated with TMB were selected: surface-to-volume ratio, total lesion glycolysis, tumor volume, area, compacity, complexity, entropy, correlation, coarseness, and zone size non-uniformity. The k-nearest neighbors model obtained the good performance for prediction of high TMB (AUC: 0.791, accuracy: 0.814, sensitivity: 0.619, specificity: 0.871). On multivariable Cox regression analysis, the PET radiomic score (Hazard ratio = 4.498, 95% confidential interval = 1.024-19.759; p = 0.046) was a significant independent prognostic factor for OS.

CONCLUSIONS

This study demonstrates that PET-based radiomics are useful image biomarkers for the prediction of TMB status in stage IV CRC. PET radiomic score, which integrates significant radiomic features, has the potential to predict survival in stage IV CRC patients.

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.

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.

Prognostic Implications of Primary Tumor Resection in Stage IVB Colorectal Cancer in Elderly Patients

PURPOSE

The aim of this study was to identify prognostic factors in stage IVB colorectal cancer in elderly patients, focusing on the influence of treatment modalities, including palliative chemotherapy and primary tumor resection.

METHODS

A cohort of 64 patients aged over 65 years who presented with stage IVB colorectal cancer at the Gangneung Asan Hospital between July 1, 2001, and December 31, 2009, was analyzed. Demographics, tumor location, tumor grade, performance status, levels of carcinoembryonic antigen (CEA), level of aspartate aminotransferase (AST), and distant metastatic site at diagnosis were analyzed. Using the treatment histories, we analyzed the prognostic implications of palliative chemotherapy and surgical resection of the primary tumor retrospectively.

RESULTS

The cohort consisted of 30 male (46.9%) and 34 female patients (53.1%); the median age was 76.5 years. Primary tumor resection was done on 28 patients (43.8%); 36 patients (56.2%) were categorized in the nonresection group. The median survival times were 12.43 months in the resection group and 3.58 months in the nonresection group (P < 0.001). Gender, level of CEA, level of AST, Eastern Cooperative Oncology Group performance status, tumor location, and presence of liver metastasis also showed significant differences in overall survival. On multivariate analysis, male gender, higher level of CEA, higher AST level, and no primary tumor resection were independent poor prognostic factors. In particular, nonresection of the primary tumor was the most potent/poor prognostic factor in the elderly-patient study group (P = 0.001; 95% confidence interval, 2.33 to 21.99; hazard ratio, 7.16).

CONCLUSION

In stage IVB colorectal cancer in elderly patients, resection of the primary tumor may enhance survival.

Surgical outcome in patients with gastrointestinal malignancies; a report from a large referral hospital, 2008-2010

BACKGROUND

A considerable portion of gastrointestinal malignancies undergoes surgerywithout curative resection. This study was conducted to assess surgical outcomein patients with gastrointestinal cancers.

METHODS

We reviewed individuals with esophagus, stomach, colon and rectum cancersadmitted for surgical treatment after initial preoperative evaluations. Surgicaloutcome, stage of tumors and 1 and 5 years survival rate were assessedand analyzed.

RESULTS

Two hundred and fifty five patients with esophagus, stomach and colorectalmalignancies, who were admitted for surgical resection, were reviewed. Twohundred and twenty two patients were underwent surgery but tumor was not resectedin 41 cases (18.6%). Based on pathological assessment, stage of tumorswas III or IV in 108 individuals (48.9%). The proportion of tumor with advancedstage was significantly higher in patients with gastroesophageal cancersthan those with colorectal malignancies (62.6% versus 31.6%), p<0.0001). Theproportion of non-resectable tumor was also significantly higher in patientswith esophageal and gastric cancers (p=0.0001). Palliative surgery was donein 26.1% of patients treated by surgical resection. The proportion of palliativesurgery was significantly lower in patients with gastric cancer (p=0.001). 1 and5-year survival were significantly longer in colorectal cancer and those withcurative surgery (p=0.001). Survival of patients with palliative resection wasthe same as patient without tumor resection.

CONCLUSION

Despite preoperative evaluations, there are still a considerable proportionof patients who are diagnosed as inoperable during surgery. Further researchesseem to be necessary in order to provide more precise preoperative staging.Screening programs should also be considered for GI cancers in high-risk areas.It seems that palliative resection would not improve survival of patientswith advanced GI malignancies.

Palliative excisional surgery for primary colorectal cancer in patients with incurable metastatic disease. Is there a survival benefit? A systematic review

AIM

Patients with stage IV colorectal cancer with unresectable metastases can either receive chemotherapy or palliative resection of the primary lesion. In the absence of any randomized data the choice of initial treatment in stage IV colorectal cancer is not based on firm evidence.

METHOD

A search of MEDLINE, Pubmed, Embase and the Cochrane Library database was performed from 1980 to 2010 for studies comparing palliative resection in stage IV colorectal cancer with other treatment modalities. Audits and observational studies were excluded. Median survival was the primary outcome measure. The morbidity and mortality of surgical and nonsurgical treatments were compared.

RESULTS

Twenty-one studies (no randomized controlled trials) were identified. Most demonstrated a survival benefit for patients who underwent palliative resection. Multivariate analysis indicates that tumour burden and performance status are both major independent prognostic variables. Selection bias, incomplete follow up and nonstandardized reporting of complications make the data difficult to interpret.

CONCLUSION

The studies indicate that there may be a survival benefit for primary resection of colorectal cancer in stage IV disease. The findings suggest that resection of the primary tumour should be based on tumour burden and performance status rather than on the presence or absence of symptoms alone.

Palliative resection of the primary tumour in stage IV rectal cancer

AIM

The aim of this study was to investigate the use of resection in a cohort of palliatively treated patients with stage IV rectal cancer. To avoid selection bias, particular attention was paid to correction for comorbidity and extent of disease.

METHOD

Patients with stage IV rectal cancer in two hospitals in Groningen were consecutively included over a 5-year period. Comorbidity was defined as major (dementia, cardiac failure or left ventricle ejection fraction <30%, or severe chronic obstructive pulmonary disease), minor (diabetes, hypertension, mild renal disease or mild pulmonary disease) or none. The effect of patient and disease characteristics on survival was assessed using Kaplan-Meier and Cox regression analyses.

RESULTS

Of 88 patients, 11 (13%) underwent elective surgical resection without chemotherapy, 15 (17%) received both elective resection and chemotherapy, 21 (24%) underwent palliative chemotherapy only and 41 (47%) had supportive care only. The extent of disease (P<0.01), hospital (P=0.02) and comorbidity (P=0.04) were correlated with worse survival. Patients treated surgically survived for longer than patients treated nonsurgically, when the data were corrected for age, comorbidity, extent of disease and hospital [hazard ratio (HR)=0.4 (95% CI=0.2-0.7)]. Perioperative morbidity was seen in 38% of the patients, and 30-day mortality was 0%.

CONCLUSION

In this retrospective cohort, resection was associated with longer survival independently of the extent of distant metastases, age and comorbidity.

Multivariate Analysis of the Survival Rate for Treatment Modalities in Incurable Stage IV Colorectal Cancer

PURPOSE

The aim of this study was to compare survival in patients that underwent palliative resection treatment versus non-resection for incurable colorectal cancer (ICRC).

METHODS

The case records of 201 patients with ICRC between January 2000 and December 2009 were reviewed. Demographics, American Society of Anesthesiologists (ASA) score, carcinoembryonic antigen (CEA) level, the location of the colon cancer, histology, metastasis, treatment options and median survival were analyzed retrospectively. We divided the patients into four groups according to the treatment modalities: resection alone, resection with post-operative chemotherapy, non-resection treatment by chemotherapy alone, and stent or bypass. Median survival times were compared according to each treatment option, and the survival rates were analyzed.

RESULTS

105 patients underwent palliative resection whereas 96 were treated with non-resection modalities. A palliative resection was performed in 44 cases for resection alone and in 61 cases for resection with post-operative chemotherapy. In patients treated with non-resection of the primary tumor, chemotherapy alone was done in 65 cases and stent or bypass in 31 cases. Multivariate analysis showed a median survival of 14 months in patients with palliative resections with post-operative chemotherapy, which was significantly higher than those for chemotherapy alone (8 months), primary tumor resection alone (5 months), and stent or bypass (5 months). Gender, age, ASA score, CEA level, the location of colon cancer, histology and the presence of multiple metastases were not independent factors in association with the median survival rate.

CONCLUSION

In the treatment of ICRC, palliative resection followed by post-operative chemotherapy shows the most favorable median survival compared to other treatment options.

Surgery of the primary in stage IV colorectal cancer with unresectable metastases

Surgery plays an important role in the treatment of patients with limited metastatic disease of colorectal cancer (CRC). Long term survival and cure is reported in 20-50% of highly selected patients with oligometastatic disease who underwent surgery. This paper describes the role of surgery of the primary tumour in patients with unresectable stage IV colorectal cancer. Owing to the increased efficacy of chemotherapeutic regimens in stage IV colorectal cancer, complications from unresected primary tumours are relatively infrequent. The risk of emergency surgical intervention is less than 15% in patients with synchronous metastatic disease who are treated with chemotherapy. Therefore, there is a tendency among surgeons not to resect the primary tumour in case of unresectable metastases. However, it is suggested that resection of the primary tumour in case of unresectable metastatic disease might influence overall survival. All studies described in the literature (n = 24) are non-randomised and the majority is single-centre and retrospective of nature. Most studies are in favour of resection of the primary tumour in patients with symptomatic lesions. In asymptomatic patients the results are less clear, although median overall survival seems to be improved in resected patients in the majority of studies. The major drawback of all these studies is that primarily patients with a better performance status and better prognosis (less metastatic sites involved) are being operated on. Another limitation of these studies is that few if any data on the use of systemic therapy are presented, which makes it difficult to assess the relative contribution of resection on outcome. Prospective studies on this topic are warranted, and are currently being planned.

CONCLUSION

Surgery of the primary tumour in patients with synchronous metastasised CRC is controversial, although data from the literature suggest that resection might be a positive prognostic factor for survival. Therefore prospective studies on the value of resection in this setting are required.

Prognostic value of resection of primary tumor in patients with stage IV colorectal cancer: retrospective analysis of two randomized studies and a review of the literature

Background

In patients with metastatic colorectal cancer (mCRC) with an asymptomatic primary tumor, there is no consensus on the indication for resection of the primary tumor.

Methods

A retrospective analysis was performed on the outcome of stage IV colorectal cancer (CRC) patients with or without resection of the primary tumor treated in the phase III CAIRO and CAIRO2 studies. A review of the literature was performed.

Results

In the CAIRO and CAIRO2 studies, 258 and 289 patients had undergone a primary tumor resection and 141 and 159 patients had not, respectively. In the CAIRO study, a significantly better median overall survival and progression-free survival was observed for the resection compared to the nonresection group, with 16.7 vs. 11.4 months [P < 0.0001, hazard ratio (HR) 0.61], and 6.7 vs. 5.9 months (P = 0.004; HR 0.74), respectively. In the CAIRO2 study, median overall survival and progression-free survival were also significantly better for the resection compared to the nonresection group, with 20.7 vs. 13.4 months (P < 0.0001; HR 0.65) and 10.5 vs. 7.8 months (P = 0.014; HR 0.78), respectively. These differences remained significant in multivariate analyses. Our review identified 22 nonrandomized studies, most of which showed improved survival for mCRC patients who underwent resection of the primary tumor.

Conclusions

Our results as well as data from literature indicate that resection of the primary tumor is a prognostic factor for survival in stage IV CRC patients. The potential bias of these results warrants prospective studies on the value of resection of primary tumor in this setting; such studies are currently being planned.

Nonresectional palliative abdominal surgery for patients with advanced colorectal cancer

OBJECTIVE

Nonresectional palliative abdominal surgery (e.g. defunctioning stoma/bypass) may be appropriate for patients unsuitable for curative resection, to deal with complications of advanced colorectal malignancy such as obstruction. Our aim was to review the outcome of surgery in these patients within our institution.

METHOD

All patients undergoing palliative surgery without resection for colorectal carcinoma between July 1998 and January 2007 were identified from our prospectively compiled colorectal cancer database. Data were extracted related to patients' demographics, presentation, tumour site, operative intervention, complications, oncological therapies, length of hospital stay and postoperative survival.

RESULTS

One hundred and ninety-three patients were identified with a median age of 79 years (31-94 years). Fifty per cent were operated on an emergent basis for obstruction or perforation, and 50% on an elective basis. One hundred and sixty-nine patients had defunctioning stomas formed of which 156 were loop stomas. Twenty-four patients underwent bypass procedures. Thirty-day mortality rate was 13.5% and postoperative morbidity rate 47%. Median survival was 247 days, with 1-year survival of 38%. Patients undergoing operation on an emergent basis had poorer long-term survival (127 vs 320 days, P = 0.002).

CONCLUSION

Nonresectional palliative abdominal surgery is associated with relatively high morbidity and mortality, particularly when performed in the emergency setting. However, in this patient group with a very poor outlook, it may be offered with reasonable survival expectations.

Intestinal complications after palliative treatment for asymptomatic patients with unresectable stage IV colorectal cancer

BACKGROUND

The initial surgical management of asymptomatic patients with unresectable stage IV colorectal cancer (CRC) is still controversy. The aim of this study was to compare the incidence of major intestinal complications in asymptomatic patients who received palliative treatment for unresectable stage IV CRC, according to the type of treatment.

METHODS

Between March 2001 and January 2008, we retrospectively analyzed 227 asymptomatic patients who underwent first-line resection of the primary tumor followed by chemotherapy (144 patients, resection group) or those who underwent first-line chemotherapy (83 patients, chemotherapy group).

RESULTS

In the resection group, the incidences of intestinal obstruction, peritonitis, fistula, and intestinal hemorrhage were 14.6%, 0%, 0.7%, and 4.8%, respectively. In the chemotherapy group, these incidences were 15.2%, 1.2%, 0%, and 3.5%, respectively. There were no significant differences between the two groups in terms of intestinal complications. In multivariate analysis of overall survival, treatment type (resection group vs. chemotherapy group) was not a significant prognostic factor (P = 0.076).

CONCLUSIONS

In asymptomatic patients with unresectable stage IV CRC, first-line chemotherapy may be considered safe, with no increased risk of major intestinal complications compared with primary tumor resection plus chemotherapy.

[Surgical treatment of liver metastasis in colorectal cancer with simultaneous liver resection]

Metastatic liver disease is a challenging and life-threatening situation often with dismal prognosis. Nearly half of the patients with colorectal cancer develop liver metastasis during the course of their diseases. Hepatic resection is the treatment of choice in patients with colorectal liver metastasis. This study was conducted to compare the results of patients undergoing simultaneous liver and colorectal resection for synchronous liver metastasis and of those for whom a colorectal and liver resection was made separately. A retrospective analysis was performed on 1597 patients who underwent surgery because of colorectal cancer between January 1999 and December 2008. The results of the treatment were separately evaluated in case of the 152 patients who had liver metastasis. The proportion of the liver metastasis was 9.52%. The metastases arose in 40.8% from the rectum and in 31.8% from the sigmoid colon. It proved to be inoperable in 109 (71.7%) of the 152 patients who had liver metastasis. Simultaneous liver resection was performed because of synchronous metastasis in 14 (32.6%) cases (Group 1) and two step resection in 29 (67.4%) cases (Group 2). In case of synchronous operations only minor liver surgery was done. The mean size of the metastasis was 2.6 cm in diameter in Group 1 and 4.6 cm in Group 2 (p<0.005). The transfused blood volume was 0.3 U/patient. Only minor complications could be observed in Group 1. The hospitalization was 13.1 days in Group 1 and 11.7 days in Group 2. The mean survival time was 37.3 and 47.9 months (p<0.005). Simultaneous liver resection seems to be a safe procedure on those patients who develop small metastases with a limited number. However, the optimal timing of the liver resection and the identification of patients who will have the greatest benefit in survival still remain obscure.

Retroperitoneal abscess complicated with necrotizing fasciitis of the thigh in a patient with sigmoid colon cancer

BACKGROUND

Necrotizing fasciitis of the thigh due to the colon cancer, especially during chemotherepy, has not been previously reported.

CASE PRESENTATION

A 67-year-old man admitted to the hospital was diagnosed with sigmoid colon cancer that had spread to the left psoas muscle. Multiple hepatic metastases were also found, and combination chemotherapy with irinotecan and S-1 was administered. Four months after the initiation of chemotherapy, the patient developed gait disturbance and high fever and was therefore admitted to the emergency department of our hospital. Blood examination revealed generalized inflammation with a high C-reactive protein level. Computed tomography of the abdomen and pelvis showed gas and fluid collection in the retroperitoneum adjacent to the sigmoid colon cancer. The abscess was locally drained under computed tomographic guidance; however, the infection continued to spread and necrotizing fasciitis developed. Consequently, emergent debridement was performed. The patient recovered well, and the primary tumor was resected after remission of the local inflammation.

CONCLUSION

Necrotizing fasciitis of the thigh due to the spread of sigmoid colon cancer is unusual, but this fatal complication should be considered during chemotherapy for patients with unresectable colorectal cancer.

Temporal trends in the proportion cured for cancer of the colon and rectum: A population-based study using data from the Finnish Cancer Registry

Colorectal cancer is the third most common cancer worldwide and the second most common cancer in Europe. Cumulative relative survival curves for both cancer of the colon and cancer of the rectum generally plateau after approximately 6-8 years. When this occurs, "population" or "statistical" cure is reached. We analyzed data from the Finnish Cancer Registry over a 50-year period using methods that simultaneously estimate the proportion of patients cured of disease (the cure fraction) and the survival time distribution of the "uncured" group. Our primary aim was to investigate temporal trends in the cure fraction and median survival of the uncured by age group for both cancer of the colon and rectum. For both cancers, the cure fraction has increased dramatically over time for all age groups. However, the difference in the cure fraction between age groups has reduced over time, particularly for cancer of the colon. Median survival in the uncured has also increased over time in all age groups but there still remains an inverse relationship between age and median survival, with shorter median survival with increasing age. The reasons for these impressive increases in patient survival are complex, but are highly likely to be strongly related to many improvements in cancer care over this same time period.