Adjuvant therapy sparing in rectal cancer achieving complete response after chemoradiation

AIM:To evaluate the long-term results of conventional chemoradiotherapy and laparoscopic mesorectal excision in rectal adenocarcinoma patients without adjuvant therapy.METHODS:Patients with biopsy-proven adenocarcinoma of the rectum staged cT3-T4 by endoscopic ultrasound or magnetic resonance imaging received neoadjuvant continuous infusion of 5-fluorouracil for five weeks and concomitant radiotherapy.Laparoscopic surgery was planned after 5-8 wk.Patients diagnosed with ypT0N0 stage cancer were not treated with adjuvant therapy according to the protocol.Patients with ypT1-2N0 or ypT3-4 or N+were offered 5-fluorouracil-based adjuvant treatment on an individual basis.An external cohort was used as a reference for the findings.RESULTS:One hundred and seventy six patients were treated with induction chemoradiotherapy and 170underwent total mesorectal excision.Cancer staging of ypT0N0 was achieved in 26/170(15.3%)patients.After a median follow-up of 58.3 mo,patients withypT0N0 had five-year disease-free and overall survival rates of 96%(95%CI:77-99)and 100%,respectively.We provide evidence about the natural history of patients with localized rectal cancer achieving a complete response after preoperative chemoradiation.The inherent good prognosis of these patients will have implications for clinical trial design and care of patients.CONCLUSION:Withholding adjuvant chemotherapy after complete response following standard neoadjuvant chemoradiotherapy and laparoscopic mesorectal excision might be safe within an experienced multidisciplinary team.

Is there a genetic signature for liver metastasis in colorectal cancer?

Even though liver metastasis accounts for the vast majority of cancer deaths in patients with colorectal cancer (CRC), fundamental questions about the molecular and cellular mechanisms of liver metastasis still remain unanswered. Determination of gene expression profiles by microarray technology has improved our knowledge of CRC molecular pathways. However, defined gene signatures are highly variable among studies. Expression profiles and molecular markers have been specifically linked to liver metastases mechanistic paths in CRC. However, to date, none of the identified signatures or molecular markers has been successfully validated as a diagnostic or prognostic tool applicable to routine clinical practice. To obtain a genetic signature for liver metastasis in CRC, measures to improve reproducibility, to increase consistency, and to validate results need to be implemented. Alternatives to expression profiling with microarray technology are continuing to be used. In the recent past, many genes codifying for proteins that are directly or indirectly involved in adhesion, invasion, angiogenesis, survival and cell growth have been linked to mechanisms of liver metastases in CRC.