Curative-intent surgery for isolated locoregional recurrence of colon cancer: Review of the literature and institutional experience

Impact of positron-emission tomography on the surgical treatment of locoregionally recurrent colorectal cancer

BACKGROUND

The effect of positron emission tomography (PET) on the surgical treatment of locoregionally recurrent colorectal cancer (LRRCRC) remains unclear and warrants further investigation.

MATERIAL AND METHODS

A total of 193 patients with LRRCRC were identified from a prospectively maintained institutional database, of whom 134 LRRCRCs were deemed resectable and underwent resection with curative intent, whereas the remaining 59 LRRCRCs were unresectable. Patients with resectable LRRCRC were further classified according to whether recurrence was detected solely by PET (n = 35, PET-only group) or by a combination of computed tomography (CT)/magnetic resonance imaging (MRI) and PET (n = 99, CT/MRI/PET group). Clinicopathologic features, operative morbidity/mortality, and overall survival were compared between the patient groups based on long-term follow-up for at least 5 years.

RESULTS

Patients in the PET-only group tended to have less extensive organ resection (p = 0.0074), less blood loss (p < 0.0001), and shorter operation time and hospitalization (p < 0.0001), but surgical complication and readmission rates were not significantly different (p > 0.05) compared with the CT/MRI/PET group. Although the PET-only group had significantly higher R0 resection rate (80 % vs. 54.55 %, p = 0.0079), they also had a higher risk (17.14 % vs. 2.02 %, p = 0.0011) of sham operation. The estimated 5-year and 10-year survival rates significantly decreased in order (p < 0.0001) from PET-only (85.71 % and 57.98 %) and CT/MRI/PET (41.41 % and 15.93 %) to unresectable group of patients (16.95 % and 1.88 %). Subset analysis of the CT/MRI/PET group indicated that PET improved surgical decision-making because 24 (24.2 %) LRRCRCs that manifested on CT/MRI as equivocal lesions were later confirmed by PET as resectable recurrences, while 18 (19.4 %) LRRCRCs that manifested on CT/MRI as resectable lesions were later diagnosed by PET as more disseminated unresectable recurrences and precluded futile surgery.

CONCLUSION

PET alone can identify a subset (20.9 %) of LRRCRCs with less tumor burden for timely surgery; PET in combination with CT/MRI can better define the resectability of LRRCRCs. The positive impacts of PET can translate into better surgical outcomes, with enhanced safety and patient survival.

Cumulative incidence of first recurrence after curative treatment of stage I-III colorectal cancer. Competing risk analyses of temporal and anatomic patterns

BACKGROUND

Updated knowledge about the rates of recurrence and time to recurrence following curative treatment of colorectal cancer is essential to secure better patient information on prognosis, to serve as a premise in the discussion on adjuvant chemotherapy, and help to properly scale the intensity and length of follow-up.

METHODS

This is a population-based study investigating aspects on first recurrence after radical treatment of clinical stages I-III of colorectal cancer in Central-Norway during 2001-2015. To reveal any time-trends, data were stratified by the time periods 2001-2005, 2006-2010 and 2011-2015. The cumulative incidence of first recurrence was calculated, treating death of unrelated causes as a competing event. Multivariable Cox analyses were done to calculate cause specific hazard ratios (HR) for risk of recurrence.

RESULTS

At a minimum follow-up of six years, a first recurrence was detected in 1,113/5,556 patients at risk (20.0%). The recurrence rate was reduced from 23.6% in the first time period, through 20.0% in the second, and to 17.2% in the last, p < 0.001. The reduction applied to all tumor locations, to pathological disease stages II and III, to both gender, across different tumor differentiations, and to both elective and emergency surgery. In multivariable analyses time period, gender, disease stage, and tumor differentiation were significant determinants for risk of recurrence.

CONCLUSIONS

The rate of first recurrence after curative surgery for colorectal cancer was substantially reduced from 2001 to 2015. The reason for the reduction could not be attributed to a single factor only. A combined effect of several incremental improvements, such as an increased use of preoperative radiation for rectal cancers, improved adjuvant chemotherapy for colon cancer, and a reduced proportion of emergency surgery, is suggested.

Epidemiology, oncologic results and risk stratification model for metachronous peritoneal metastases after surgery for pT4 colon cancers: results from an observational retrospective multicentre long-term follow-up study

PURPOSE

Metachronous peritoneal metastases (MPM) following a curative surgery procedure for pT4 colon cancer is a challenging condition. Current epidemiological studies on this topic are scarce.

METHODS

A retrospective multicentre trial was designed. All consecutive patients who underwent operations to treat pT4 cancers between 2015 and 2017 were reviewed. Demographic, clinical, operative, pathological and oncological follow-up variables were included. MPM were described as any oncological disease at the peritoneum, clearly different from a local recurrence. Univariate and multivariate Cox regression models were constructed. A risk stratification model was created on a cumulative factor basis. According to the calculated hazard ratio (HR), a scoring system was designed (HR < 3, 1 point; HR > 3, 2 points) and a scale from 0 to 6 was calculated for peritoneal disease-free rate (PDF-R). A risk stratification model was also created on the basis of these calculations.

RESULTS

Fifty different hospitals were involved, which included a total of 1356 patients. Incidence of MPM was 13.6% at 50 months median follow-up. The strongest independent risk factors for MPM were positive pN stage [HR 3.72 (95% CI 2.56-5.41; p < 0.01) for stage III disease], tumour perforation [HR 1.91 (95% CI 1.26-2.87; p < 0.01)], mucinous or signet ring cell histology [HR 1.68 (95% CI 1.1-2.58; p = 0.02)], poorly differentiated tumours [HR 1.54 (95% CI 1.1-2.2; p = 0.02)] and emergency surgery [HR 1.42 (95% CI 1.01-2.01; p = 0.049)]. In the absence of additional risk factors, pT4 tumours showed 98% and 96% PDF-R in 1-year and 5-year periods based on Kaplan-Meier curves.

CONCLUSIONS

Cumulative MPM incidence was 13.6% at 5-year follow-up. The sole presence of a pT4 tumour resulted in high rates of PDF-R at 1-year and 5-year follow-up (98% and 96% respectively). Five additional risk factors different from pT4 status itself were identified as possible MPM indicators during follow-up.

Locoregionally Recurrent Colon Cancer: How Far Have We Come? A Population-Based, Retrospective Cohort Study

BACKGROUND

The reported outcomes of locoregionally recurrent colon cancer (LRCC) are poor, but the literature about LRCC is scarce and aged. Recent population-based studies to provide current insight into LRCC are warranted. This study aimed to provide an overview of the incidence, risk factors, treatment, and overall survival (OS) of patients with LRCC after curative resection of stage I-III primary colon cancer.

METHODS

Data on disease recurrence were collected for all patients with a diagnosis of non-metastasized primary colon cancer in the Netherlands during the first 6 months of 2015. Patients who underwent surgical resection (N = 3544) were included in this study. The 3-year cumulative incidence, risk factors, treatment, and OS for patients with LRCC were determined.

RESULTS

The 3-year cumulative incidence of LRCC was 3.8%. Synchronous distant metastases (LRCC-M1) were diagnosed in 62.7% of the patients. The risk factors for LRCC were age of 70 years or older, pT4, pN1-2, and R1-2. Adjuvant chemotherapy was associated with a decreased risk of LRCC for high-risk stage II and stage III patients [hazard ratio (HR), 0.47; 95% confidence interval (CI) 0.31-0.93]. The median OS for the patients with LRCC was 13.1 months (95% CI 9.1-18.3 months). Curative-intent treatment was given to 22.4% of the LRCC patients, and the subsequent 3 years OS was 71% (95% CI 58-87%). The patients treated with palliative treatment and best supportive care showed 3-year OS rates of 15% (95% CI 7.0-31%) and 3.7% (95% CI 1.0-14%), respectively.

CONCLUSIONS

The cumulative incidence of LRCC was low, and adjuvant chemotherapy was associated with a decreased risk for LRCC among targeted patients. Curative-intent treatment was given to nearly 1 in 4 LRCC patients, and the OS for this group was high.

Risk of metachronous peritoneal metastases in patients with pT4a versus pT4b colon cancer: An international multicentre cohort study

INTRODUCTION

With evolving treatment strategies aiming at prevention or early detection of metachronous peritoneal metastases (PM), identification of high-risk colon cancer patients becomes increasingly important. This study aimed to evaluate differences between pT4a (peritoneal penetration) and pT4b (invasion of other organs/structures) subcategories regarding risk of PM and other oncological outcomes.

MATERIALS AND METHODS

From eight databases deriving from four countries, patients who underwent curative intent treatment for pT4N0-2M0 primary colon cancer were included. Primary outcome was the 5-year metachronous PM rate assessed by Kaplan-Meier analysis. Independent predictors for metachronous PM were identified by Cox regression analysis. Secondary endpoints included 5-year local and distant recurrence rates, and 5-year disease free and overall survival (DFS, OS).

RESULTS

In total, 665 patients with pT4a and 187 patients with pT4b colon cancer were included. Median follow-up was 38 months (IQR 23-60). Five-year PM rate was 24.7% and 12.2% for pT4a and pT4b categories, respectively (p = 0.005). Independent predictors for metachronous PM were female sex, right-sided colon cancer, peritumoral abscess, pT4a, pN2, R1 resection, signet ring cell histology and postoperative surgical site infections. Five-year local recurrence rate was 14% in both pT4a and pT4b cancer (p = 0.138). Corresponding five-year distant metastases rates were 35% and 28% (p = 0.138). Five-year DFS and OS were 54% vs. 62% (p = 0.095) and 63% vs. 68% (p = 0.148) for pT4a vs. pT4b categories, respectively.

CONCLUSION

Patients with pT4a colon cancer have a higher risk of metachronous PM than pT4b patients. This observation has important implications for early detection and future adjuvant treatment strategies.