Stage dependent recurrence patterns and post-recurrence outcomes in non-metastatic colon cancer.

BACKGROUND: Multiple meta-analyses have demonstrated that routine surveillance following colorectal cancer surgery improves survival outcomes. There is limited data on how recurrence patterns and post-recurrence outcomes vary by individual tumor stage. METHODS: Using a multi-site community cohort study, we examined the potential impact of primary tumor stage on the sites of recurrence, management of recurrent disease with curative intent, and post-resection survival. We also explored changes over time. RESULTS: Of 4257 new colon cancers diagnosed 2001 through 2016, 789 (21.1%) had stage I, 1584 (42.4%) had stage II, and 1360 (36.4%) had stage III colon cancer. For consecutive 5-year periods (2001-2005, 2006-2010, 2011-2016), recurrence rates have declined (23.4 vs. 17.1 vs. 13.6%, p < 0.001), however, the resection rates of metastatic disease (29.3 vs. 38.6 vs. 35.0%, p = 0.21) and post-resection 5-year survival (52.0 vs. 51.8 vs. 64.2%, p = 0.12) have remained steady. Primary tumor stage impacted recurrence rate (3.8 vs. 12 vs. 28%, p < 0.0001 for stage 1, 2, and 3), patterns of recurrence, resection of metastatic disease, (50 vs. 42 vs. 30%, p < 0.0001) and post-resection 5-year survival (92 vs. 64 vs. 44%, p < 0.001). CONCLUSION: In this community cohort we defined significant differences in recurrence patterns and post-resection survival by tumor stage, with a diminishing rate of recurrence over time. While recurrence rates were lower with stage I and II disease, the high rate of metastatic disease resection and excellent post-resection outcomes help to justify routine surveillance in these patients.

Chemotherapy and biologic use in the routine management of metastatic colorectal cancer in Australia: is clinical practice following the evidence?

BACKGROUND: Emerging evidence on the optimal use of chemotherapy and biologics in patients with metastatic colorectal cancer should impact management in routine care. Recent studies have demonstrated benefits for initial triplet chemotherapy (5-fluorouracil, oxaliplatin and irinotecan, FOLFOXIRI) and for initial treatment with an epidermal growth factor receptor inhibitor (EGFRi) in patients with a RAS wild-type tumour and a left-sided primary tumour. AIM: To explore evolving pattern of metastatic colorectal cancer care over time in Australia. METHODS: We analysed data from the Treatment of Recurrent and Advanced Colorectal Cancer registry. RESULTS: From July 2009 to December 2017, 2552 metastatic colorectal cancer patients were entered into the Treatment of Recurrent and Advanced Colorectal Cancer registry. Of 1585 patients who initially underwent chemotherapy, treatment was with a doublet in 76%. FOLFOXIRI was given to 22 patients (1.4%), mostly young patients and those with potentially resectable disease. Along with first-line chemotherapy, 61% received bevacizumab, while 3.3% received an EGFRi, predominantly over the last 2 years. Within the KRAS wild-type left-sided tumour cohort, EGFRi use increased from 9% in 2015 to 37% in 2017. Across treatment sites, there was a wide variation in the utilisation of FOLFOXIRI and EGFRi therapy; bevacizumab use was more consistent. A clear impact on survival outcomes from these regimens is not evident, potentially due to multiple confounders. CONCLUSION: Doublet chemotherapy + bevacizumab remains the dominant initial strategy, with limited uptake of triplet chemotherapy and of EGFRi. Potential explanations include uncertainty about the significance of post hoc analyses for EGFRi and concerns regarding adverse events for both strategies.

Mismatch repair deficiency assessment by immunohistochemistry: for Lynch syndrome screening and beyond.

While mismatch repair (MMR) deficiency has been studied extensively, the assessment of MMR status in colorectal and other cancers remains highly relevant, particularly in light of recent data demonstrating that MMR deficiency is a strong predictor for treatment benefit with immune checkpoint inhibitors across multiple tumor types. In colorectal cancer, there is a growing consensus in support of routine MMR testing for Lynch syndrome screening, to inform prognosis and adjuvant chemotherapy use in early stage disease, and to predict response to immunotherapy in advanced disease. Here, we provide a review of the Ventana MMR Immunohistochemistry Panel, which was recently approved by the US FDA for use in Lynch syndrome screening.

DNA in extracellular vesicles: biological and clinical aspects.

The study of extracellular vesicles (EVs), especially in the liquid biopsy field, has rapidly evolved in recent years. However, most EV studies have focused on RNA or protein content and DNA in EVs (EV-DNA) has largely been unnoticed. In this review, we compile current evidence regarding EV-DNA and provide an extensive discussion on EV-DNA biology. We look into EV-DNA biogenesis and mechanisms of DNA loading into EVs, as well as describe the particularly significant function of DNA-carrying EVs in the maintenance of cellular homeostasis, intracellular communication, and immune response modulation. We also examine the current role of EV-DNA in the clinical setting, specifically in cancer, infections, pregnancy, and prenatal diagnosis.

Real-World Treatment and Outcomes of Metastatic Colorectal Cancer Patients With a Poor or Very Poor Performance Status.

BACKGROUND: The management of metastatic colorectal cancer patients with a poor performance status (PS) continues to be a clinical dilemma, with the potential activity and safety of treating this population remaining poorly understood. Few of these patients are enrolled onto clinical trials, and poor PS is often multifactorial. PATIENTS AND METHODS: We analyzed the Treatment of Recurrent and Advanced Colorectal Cancer registry to describe treatment practices and outcomes in poor (Eastern Cooperative Oncology Group [ECOG] PS 2) and very poor PS (ECOG PS > 2) patients to explore the relationship between age, tumor burden, comorbidities, and PS, and to evaluate the benefit of systemic therapy. Standard descriptive statistical methods, Kaplan-Meier analysis, and a multivariate Cox regression model were used. RESULTS: Of 2769 registry patients (diagnosed January 2009 to June 2018), 329 (12%) and 182 (7%) patients had a poor and very poor PS, respectively. Good PS patients were more likely to receive systemic therapy than poor and very poor PS patients (85%, 55%, and 21.5%, P < .0001), but clinician assessed response was observed in all subsets (53%, 41%, and 29%, P = .0003). Treatment with chemotherapy was associated with longer median overall survival across PS groups. Exploratory analysis based on comorbidity score and tumor burden subgroups demonstrated a consistently positive overall survival association with treatment. Benefit was observed where poor overall survival was attributable to medical comorbidities and to tumor burden. CONCLUSION: In routine clinical care, a substantial proportion of poor and very poor PS patients receive active treatment, which is often associated with meaningful clinical benefit.

Resection of colorectal cancer liver metastases in older patients.

BACKGROUND: Colorectal cancer remains a common cancer in the western world, with liver resection being the only potentially curative option for isolated colorectal cancer liver metastases (CRCLM). Cancer is a disease of aging, with the optimum management of elderly patients with CRCLM presenting an ongoing dilemma. METHODS: We analysed the outcome of CRCLM using prospectively collected patient data from the multidisciplinary Treatment of Recurrent and Advanced Colorectal Cancer registry, collected from July 2009 to July 2018 at 12 Australian hospitals. RESULTS: Of 2742 patients with metastatic colorectal cancer, liver-limited disease was present in 977 (36%) patients, of whom 338 (35%) underwent hepatic resection. Resection rates varied with age, including 186 (43%) of 428 patients aged 64 years and younger, 99 (40%) of 245 aged 65-75 years and 53 (17%) of 303 aged 76 and older (P < 0.001). The 30-day mortality rate was 0.9%. Median survival post resection also varied with age, 96 versus 89 versus 68 months (P < 0.001). In a separate analysis of the oldest patients, those aged over 80 years, where only 11% underwent resection, the median survival was 49 months. CONCLUSION: The operative mortality for patients undergoing liver resection at Australian hospitals is low. With advancing age, the rate of liver resection of CRCLM and the post-resection survival decline. However, excellent survival outcomes can be achieved in selected elderly patients.

Previous Bevacizumab and Efficacy of Later Anti-Epidermal Growth Factor Receptor Antibodies in Metastatic Colorectal Cancer: Results From a Large International Registry.

BACKGROUND: The FIRE-3 [5-fluorouracil, folinic acid, and irinotecan (FOLFIRI) plus cetuximab versus FOLFIRI plus bevacizumab in first line treatment colorectal cancer (CRC)] study reported that first-line FOLFIRI plus cetuximab versus FOLFIRI plus bevacizumab resulted in similar progression-free survival (PFS) but improved overall survival (OS). A potential explanation is that the initial biologic agent administered in metastatic CRC (mCRC) affects later line efficacy of the other treatments. We sought to test this hypothesis. MATERIALS AND METHODS: We interrogated our mCRC registry (Treatment of Recurrent and Advanced Colorectal Cancer) regarding treatment and outcome data for RAS wild-type patients receiving epidermal growth factor receptor inhibitors (EGFRIs) in second and subsequent lines. Survival outcomes from the beginning of EGFRI use were determined as a function of previous bevacizumab use and the interval between ceasing bevacizumab and beginning EGFRI use. RESULTS: Of 2061 patients, 222 eligible patients were identified, of whom 170 (77%) had received previous bevacizumab and 52 (23%) had not. PFS and OS from the start of EGFRIs did not differ by previous bevacizumab use (3.8 vs. 4.2 months; hazard ratio [HR], 1.12; P = .81; 9.0 vs. 9.2 months; HR, 1.19; P = .48, respectively) for the whole cohort or when analyzed by the primary tumor side (HR for left side, 1.07; P = .57; HR for right side, 1.2; P = .52). PFS was significantly shorter with right-sided primary tumors when the interval between bevacizumab and EGFRI use was < 6 versus > 6 months (median, 2.2 vs. 6 months; HR, 2.23; P = .01) but not with left-sided tumors (median, 4.2 vs. 5.5 months; HR, 1.12; P = .26). CONCLUSION: Previous bevacizumab use had no effect on the activity of subsequent EGFRIs. The apparent effect of time between biologic agents in right-sided tumors might reflect patient selection.

Stage-based Variation in the Effect of Primary Tumor Side on All Stages of Colorectal Cancer Recurrence and Survival.

BACKGROUND: Multiple studies have defined the prognostic and potential predictive significance of the primary tumor side in metastatic colorectal cancer (CRC). However, the currently available data for early-stage disease are limited and inconsistent. MATERIALS AND METHODS: We explored the clinicopathologic, treatment, and outcome data from a multisite Australian CRC registry from 2003 to 2016. Tumors at and distal to the splenic flexure were considered a left primary (LP). RESULTS: For the 6547 patients identified, the median age at diagnosis was 69 years, 55% were men, and most (63%) had a LP. Comparing the outcomes for right primary (RP) versus LP, time-to-recurrence was similar for stage I and III disease, but longer for those with a stage II RP (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.52-0.90; P < .01). Adjuvant chemotherapy provided a consistent benefit in stage III disease, regardless of the tumor side. Overall survival (OS) was similar for those with stage I and II disease between LP and RP patients; however, those with stage III RP disease had poorer OS (HR, 1.30; 95% CI, 1.04-1.62; P < .05) and cancer-specific survival (HR, 1.55; 95% CI, 1.19-2.03; P < .01). Patients with stage IV RP, whether de novo metastatic (HR, 1.15; 95% CI, 0.95-1.39) or relapsed post-early-stage disease (HR, 1.35; 95% CI, 1.11-1.65; P < .01), had poorer OS. CONCLUSION: In early-stage CRC, the association of tumor side and effect on the time-to-recurrence and OS varies by stage. In stage III patients with an RP, poorer OS and cancer-specific survival outcomes are, in part, driven by inferior survival after recurrence, and tumor side did not influence adjuvant chemotherapy benefit.