Combinatie van chemo en radiotherapie vooraf aan operatie van rectumkanker - endeldarmkanker geeft significant betere resultaten op de tumorgrootte en lymfklieruitzaaiingen bij de operatie dan vooraf alleen bestraling

11 november 2011: klik hier voor de meest recente studie naar effecten van bestraling en chemo vooraf aan operatie op die operatie zelf bij patienten met niet uitgezaaide rectumkanker - endeldarmkanker volgens recente Nederlandse studie

30 november 2005: Bron: J Clin Oncol. 2005;23:5620-5627 en Clinical Options.

Een grote langjarige gerandomiseerde Europese fase III studie bevestigt dat wanneer operabele rectumkankerpatiënten vooraf aan de operatie chemo en bestraling krijgen de tumoren bij operatie kleiner waren, minder lymfklieruitzaaiïngen en gemakkelijker te opereren waren. De onderzoekers benadrukken dat het effect op de tumorgrootte enz. geen bewijs is dat deze aanpak ook voor langduriger overleving of meer overlevingen zorgt. Hier een artikel over deze studie van Clinical Options.

Preoperative chemoradiotherapy superior to radiotherapy alone in patients with rectal cancer
By Mindy Tanzola
November 01, 2005

Patients treated with preoperative chemoradiotherapy (RT-CT) exhibited superior pathologic and histologic characteristics at the time of surgery compared with those receiving radiotherapy (RT) alone, according to a recent study published in the Journal of Clinical Oncology.

Over the past several decades, much controversy has surrounded the issue of neoadjuvant and adjuvant therapies in the treatment of colorectal cancer. In 1989, the National Institutes of Health recommended postoperative RT-CT as standard treatment for patients with stage II or III rectal cancer.

Subsequent studies indicated a potential benefit for preoperative RT-CT, which led to the wide acceptance of this approach in the United States. However, preoperative RT alone has remained the standard treatment approach in Europe.

These treatment approaches have not been compared in a large-scale randomized trial. For this reason, the European Organisation for Research and Treatment of Cancer (EORTC) launched the current 22921 trial.

Jean-Francois Bosset, MD, of the Besançon University Hospital, France, and colleagues enrolled 1011 patients with T3 or resectable T4 rectal adenocarcinoma to receive preoperative RT (45 Gy over 5 weeks) with or without chemotherapy (n = 505) consisting of two 5-day courses of 350 mg/m2/day of fluorouracil plus 20 mg/m2/day of leucovorin given concurrently during Weeks 1 and 5 of RT.

The tumor was subsequently resected in 476 and 473 patients in the RT and RT-CT groups, respectively. Patients treated with RT-CT had smaller tumors compared with RT-treated patients (mean size, 25.0 mm vs 30.0 mm; P < .001). They also showed significantly lower tumor stage (P < .001) and had significantly less lymph node involvement (P < .001). Histologically, specimens from patients treated with RT-CT were less likely to demonstrate lymphatic, venous, or perineural invasion (P ≤ .001 for each) compared with RT-treated patients.

However, the researchers caution that these results are preliminary. They also point out that the “observed enhanced tumoricidal effects of RT-CT should in no case be regarded as a surrogate indication for a longer-term treatment effect on locoregional control or survival.”

Patients are being further randomized to postoperative chemotherapy vs observation. According to the researchers, subsequent follow-up should provide important information regarding potential benefits of chemotherapy and/or RT at different stages of treatment for rectal cancer.

Reference

Bosset JF, Calais G, Mineur L, et al. Enhanced tumorocidal effect of preoperative radiotherapy on rectal cancer by adding chemotherapy: preliminary results from the 22921 European Organization for Research and Treatment of Cancer randomized trial. J Clin Oncol. 2005;23:5620-5627.