Histological growth patterns and molecular analysis of resected colorectal lung metastases

The Management of Oligometastatic Disease in Colorectal Cancer: Present Strategies and Future Perspectives

Oligometastatic disease has been described as an intermediate clinical state between localized cancer and systemically metastasized disease. Recent clinical studies have shown prolonged survival when aggressive locoregional approaches are added to systemic therapies in patients with oligometastases. The aim of this review is to outline the newest options to treat oligometastatic colorectal cancer (CRC), also considering its molecular patterns. We present an overview of the available local treatment strategies, including surgical procedures, stereotactic body radiation therapy (SBRT), thermal ablation, as well as trans-arterial chemoembolization (TACE) and selective internal radiotherapy (SIRT). Moreover, since imaging methods provide crucial information for the early diagnosis and management of oligometastatic CRC, we discuss the role of modern radiologic techniques in selecting patients that are amenable to potentially curative locoregional treatments.

The prognostic value of KRAS mutation in locally advanced rectal cancer

BACKGROUND

The prognostic value of the KRAS proto-oncogene mutation in colorectal cancer has been debated. Herein, we analyzed the National Cancer Database (NCDB) to assess the role of KRAS mutation as a prognostic marker in patients with locally advanced rectal cancer (LARC).

METHODS

We identified LARC patients treated with neoadjuvant chemoradiation from 2004-2015 excluding those with stage I/IV disease and unknown KRAS status. Multivariable logistic regression identified variables associated with KRAS positivity. Propensity adjusted univariable and multivariable analyses identified predictors of survival.

RESULTS

Of the 784 eligible patients, 506 were KRAS-negative (KRAS -) and 278 were KRAS-positive (KRAS +). Median survival was 63.6 months and 76.3 months for KRAS + and KRAS - patients respectively, with propensity adjusted 3 and 5-year survival of 79.9% vs. 83.6% and 56.7% vs. 61.9% respectively (HR 1.56, p 1.074-2.272). Male sex, no insurance, and KRAS + disease were associated with poorer survival on unadjusted and propensity adjusted multivariable analyses.

CONCLUSIONS

Our analysis of KRAS + LARC suggest that KRAS + disease is associated with poorer overall survival. Given the inherent limitations of retrospective data, prospective validation is warranted.

Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomised controlled trial: a systematic review of published responses

OBJECTIVES

The objective of this review was to assess the nature and tone of the published responses to the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) randomized controlled trial.

METHODS

Published articles that cited the PulMiCC trial were identified from Clarivate Web of Science (©. Duplicates and self-citations were excluded and relevant text extracted. Four independent researchers rated the extracts independently using agreed scales for the representativeness of trial data and the textual tone. The ratings were aggregated and summarized. Two PulMiCC authors carried out a thematic analysis of the extracts.

RESULTS

Sixty-four citations were identified and relevant text was extracted and examined. The consensus rating for data inclusion was a median of 0.25 out of 6 (range 0 to 5.25, IQR 0-1.5) and for textual tone the median rating was 1.87 out of 6 (range 0 to 5.75, IQR 1-3.5). The majority of citations did not provide adequate representation of the PulMiCC data and the overall the textual tone was dismissive. Although some were supportive, many discounted the findings because the trial closed early and was underpowered to show non-inferiority. Two misinterpreted the authors' conclusions but there was acceptance that five-year survival was much higher than widely assumed.

CONCLUSIONS

Published comments reveal a widespread reluctance to consider seriously the results of a carefully conducted randomized trial. This may be because the results challenge accepted practice because of 'motivated reasoning'. But there is a widespread misunderstanding of the fact that though PulMiCC with 93 patients was underpowered to test non-inferiority, it still provides reliable evidence to undermine the widespread belief in a major survival benefit from metastasectomy.

The Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) burden of care study: Analysis of local treatments for lung metastases and systemic chemotherapy in 220 patients in the PulMiCC cohort

AIM

The aim of this work was to examine the burden of further treatments in patients with colorectal cancer following a decision about lung metastasectomy.

METHOD

Five teams participating in the Pulmonary Metastasectomy in Colorectal Cancer (PulMiCC) study provided details on subsequent local treatments for lung metastases, including the use of chemotherapy. For patients in three groups (no metastasectomy, one metastasectomy or multiple local interventions), baseline factors and selection criteria for additional treatments were examined.

RESULTS

The five teams recruited 220 patients between October 2010 and January 2017. No lung metastasectomy was performed in 51 patients, 114 patients had one metastasectomy and 55 patients had multiple local interventions. Selection for initial metastasectomy was associated with nonelevated carcinoembryonic antigen, fewer metastases and no prior liver metastasectomy. These patients also had better Eastern Cooperative Oncology Group scores and lung function at baseline. Four sites provided information on chemotherapy in 139 patients: 79 (57%) had one to five courses of chemotherapy, to a total of 179 courses. The patterns of survival after one or multiple metastasectomy interventions showed evidence of guarantee-time bias contributing to an impression of benefit over no metastasectomy. After repeated metastasectomy, a significantly higher risk of death was observed, with no apparent reduction in chemotherapy usage.

CONCLUSION

Repeated metastasectomy is associated with a higher risk of death without reducing the use of chemotherapy. Continued monitoring without surgery might reassure patients with indolent disease or allow response assessment during systemic treatment. Overall, the carefully collected information from the PulMICC study provides no indication of an important survival benefit from metastasectomy.

The current understanding on the impact of KRAS on colorectal cancer

KRAS (kirsten rat sarcoma viral oncogene) is a member of the RAS family. KRAS mutations are one of most dominant mutations in colorectal cancer (CRC). The impact of KRAS mutations on the prognosis and survival of CRC patients drives many research studies to explore potential therapeutics or target therapy for the KRAS mutant CRC. This review summarizes the current understanding of the pathological consequences of the KRAS mutations in the development of CRC; and the impact of the mutations on the response and the sensitivity to the current front-line chemotherapy. The current therapeutic strategies for treating KRAS mutant CRC, the difficulties and challenges will also be discussed.