Early stage colon cancer: Current treatment standards, evolving paradigms, and future directions

Abstract

Colon cancer continues to be one of the leading causes of mortality and morbidity throughout the world despite the availability of reliable screening tools and effective therapies. The majority of patients with colon cancer are diagnosed at an early stage (stages I to III), which provides an opportunity for cure. The current treatment paradigm of early stage colon cancer consists of surgery followed by adjuvant chemotherapy in a select group of patients, which is directed at the eradication of minimal residual disease to achieve a cure. Surgery alone is curative for the vast majority of colon cancer patients. Currently, surgery and adjuvant chemotherapy can achieve long term survival in about two-thirds of colon cancer patients with nodal involvement. Adjuvant chemotherapy is recommended for all patients with stage III colon cancer, while the benefit in stage II patients is not unequivocally established despite several large clinical trials. Contemporary research in early stage colon cancer is focused on minimally invasive surgical techniques, strategies to limit treatment-related toxicities, precise patient selection for adjuvant therapy, utilization of molecular and clinicopathologic information to personalize therapy and exploration of new therapies exploiting the evolving knowledge of tumor biology. In this review, we will discuss the current standard treatment, evolving treatment paradigms, and the emerging biomarkers, that will likely help improve patient selection and personalization of therapy leading to superior outcomes.

Keywords: Adjuvant; Circulating tumor DNA; Immunoscore; Minimally invasive; Neoadjuvant; FOxTROT; Minimal residual disease; International duration evaluation of adjuvant chemotherapy

Core tip: Although the majority of patients with colon cancer are diagnosed in an early stage, cancer recurrence after initial curative therapy is frequent, underscoring the need for novel approaches. The challenges in the current treatment paradigm include the lack of precise patient selection tools for adjuvant therapy, disabling toxicities, and modest efficacy of the adjuvant therapies. Herein we provide a contemporaneous appraisal of the early stage colon cancer treatment and discuss how evolving technologies, including circulating tumor DNA, can potentially transform the standard of care.