Postoperative adjuvant chemotherapy in rectal cancer operated for cure

Monthly tegafur-uracil maintenance for increasing relapse-free survival in ypStage III rectal cancer patients after preoperative radiotherapy, radical resection, and 12 postoperative chemotherapy cycles: a retrospective study

BACKGROUND

Current advancements in neoadjuvant therapy and total mesorectal excision have engendered increased local control. However, the survival benefit of preoperative radiotherapy (RT; 5 × 5 Gy) in rectal cancer patients remains inadequate, primarily because of systemic recurrence. In this retrospective single-center study, the effects of monthly tegafur-uracil maintenance (≥6 cycles) after 12 fluorouracil-based adjuvant chemotherapy cycles on 3-year relapse-free survival (RFS) was estimated in ypStage III rectal cancer patients.

METHODS

Of ypStage III rectal cancer patients who received preoperative RT (5 × 5 Gy) in January 2006-December 2015, those who had ypStage III cancer after preoperative radiation, radical resection, and postoperative chemotherapy were enrolled; excluded patients had ypStage I and II rectal cancer, had double cancer, had synchronous distant metastasis, had local excision, received preoperative chemoradiation, and were lost to follow-up within 1 year after cancer treatment. Included patients received either maintenance therapy or observation after postoperative chemotherapy. The primary endpoint was the effect of maintenance therapy on 3-year RFS. We set the median follow-up duration to be 69.7 (range, 15.4-148.3) months.

RESULTS

Of 259 ypStage III rectal cancer patients, 102 (59 men and 43 women) were enrolled based on the inclusion criteria. The maintenance and observation groups comprised 55 and 57 patients, respectively (mean age = 62.2 and 65.7 years, respectively; p = 0.185). The 3-year RFS observed in the maintenance group (85.1%) was longer than that observed in the observation group (67.5%; p = 0.039). Multivariate analysis proved the following to be independent prognostic factors for RFS: higher metastatic lymph node ratio (LNR ≥0.3), tegafur-uracil maintenance (≥6 cycles), and lower rectal cancer (< 6 cm from the anal verge). The higher the rectal cancer location (≥6 cm from the anal verge) was, the higher the tegafur-uracil maintenance survival benefit became (p = 0.041). Moreover, lower cancer location (< 6 cm from the anal verge) and LNR ≥0.3 were both associated with a trend of longer RFS after tegafur-uracil maintenance therapy (p = 0.164 and 0.113, respectively).

CONCLUSIONS

After the execution of fluorouracil-based adjuvant chemotherapy, administering monthly tegafur-uracil (≥6 cycles) may improve the 3-year RFS of ypStage III rectal cancer patients.

Colorectal cancer: from prevention to personalized medicine

Colorectal cancer (CRC) is a very heterogeneous disease that is caused by the interaction of genetic and environmental factors. CRC develops through a gradual accumulation of genetic and epigenetic changes, leading to the transformation of normal colonic mucosa into invasive cancer. CRC is one of the most prevalent and incident cancers worldwide, as well as one of the most deadly. Approximately 1235108 people are diagnosed annually with CRC, and 609051 die from CRC annually. The World Health Organization estimates an increase of 77% in the number of newly diagnosed cases of CRC and an increase of 80% in deaths from CRC by 2030. The incidence of CRC can benefit from different strategies depending on its stage: health promotion through health education campaigns (when the disease is not yet present), the implementation of screening programs (for detection of the disease in its early stages), and the development of nearly personalized treatments according to both patient characteristics (age, sex) and the cancer itself (gene expression). Although there are different strategies for screening and although the number of such strategies is increasing due to the potential of emerging technologies in molecular marker application, not all strategies meet the criteria required for screening tests in population programs; the three most accepted tests are the fecal occult blood test (FOBT), colonoscopy and sigmoidoscopy. FOBT is the most used method for CRC screening worldwide and is also the primary choice in most population-based screening programs in Europe. Due to its non-invasive nature and low cost, it is one of the most accepted techniques by population. CRC is a very heterogeneous disease, and with a few exceptions (APC, p53, KRAS), most of the genes involved in CRC are observed in a small percentage of cases. The design of genetic and epigenetic marker panels that are able to provide maximum coverage in the diagnosis of colorectal neoplasia seems a reasonable strategy. In recent years, the use of DNA, RNA and protein markers in different biological samples has been explored as strategies for CRC diagnosis. Although there is not yet sufficient evidence to recommend the analysis of biomarkers such as DNA, RNA or proteins in the blood or stool, it is likely that given the quick progression of technology tools in molecular biology, increasingly sensitive and less expensive, these tools will gradually be employed in clinical practice and will likely be developed in mass.