impact of pet scan on the curative strategy of colo-rectal cancers : a randomized study

Conditions: Colorectal Cancer

Summary: the risk of recurrence in stage iii and iv of colorectal cancers (crc) is high during the three years following the tumoral resection with curative aim. therefore, a prolonged follow-up and an intense monitoring are recommended to detect these recurrences precociously. nevertheless, current consensual morphological and biological examinations are not very contributory, of difficult interpretation and expensive. the metabolic imagery in tomoscintigraphy by emission of positron coupled with the scanner, called pet-tdm, allows to identify more specifically recurrences, analyzes the whole body, detects hepatic metastasis more precociously and give some benefice for early diagnosis of lymph nodes recurrence. the principle purpose of this study is to evaluate if the systematic follow-up per pet-tdm allows detecting more often recurrences accessible to a curative surgery. we make the hypothesis that the systematic practice of pet- tomodensitometry (tdm) during the follow-up of crc allows to decrease non curative recurrences appearance during the 3 years follow-up after a curative surgery.

patients will be randomized in two groups: one (pet-tdm group) including a semi-annual systematic pet-tdm during usual follow-up (m6, m12, m18, m24, m30 and m36 after initial surgery) and the second (control group) in which one pet-tdm will be realized only for current indication (high isolated markers or before a metastasis curative resection) during usual follow-up. will be included patients with a high risk of recurrence of a colorectal tumor n+ or m+ completely removed (r0 or r1) or tumor stage 4, no regional lymph node metastasis, no distant metastasis (t4n0m0) operated in emergency (tumoral perforation). patients will be followed-up during 3 years since the date of initial surgery. conventional follow-up will be performed by consensual recommendations for all the patients. in the case of detecting a recurrence, the adapted treatment (surgery or chemotherapy or both) with curative aim will be implemented and the follow-up will be carried out in its term or death. in the case of non curable recurrence, the follow-up will be carried out in its term or death, and the pet-tdm will not be realised any more.

Eligibility criteria:
inclusion criteria: * patients with a removed colorectal adenocarcinoma since less than 6 months, in total remission and for whom a monitoring is necessary to detect recurrences precociously. * patients with a removed colorectal tumour which is histologically proved and classified n+ and/or m+ (stage iii or iv). hepatic and/or pulmonary metastasis would have been totally removed since less 6 months before inclusion. * patients with a t4n0m0 tumour and operated in emergency (because of a tumoral perforation) can be included. (suppressed by amendment 1) * 2 before criteria have been replaced by : patients with colorectal adenocarcinoma which is histologically proved and classified stage ii perforated, iii or iv, totally removed, in total remission, * if no metastatic, removed surgery must have been done since less 6 months; * if metastatic, all metastasis would have been removed, the last surgery dating less 6 months.(amendment 1) * casual extension check-up would have been realized before initial surgery or during a period of 6 months after surgery performed in emergency. * informed consent signed * age ≥ 18 years * patient in ability to undergone hepatic or pulmonary resection in case of recurrence during the follow-up (ecog ≤ 2) * willingness to control visits exclusion criteria: * pregnant or breast feeding women, or with a reproductive potential and no practicing an effective method of contraception during the second part of ovarian cycle ( pet is realised during the first part of ovarian cycle) * cancer stage i or ii (except t4 operated in emergency) or iv without possibility to remove metastasis or r2 after surgery. * performance status contraindicating a hepatic or pulmonary surgery in case of recurrence. * patients likely to undergone chemotherapy, surgery or radiotherapy during 2 weeks before pet-tdm. * other progressive tumoral affection known, or colorectal cancer in progression. • (bad compliance to the study procedure.)(suppressed by amendment 1) * not balanced diabetes. (added by amendment 1) * patients included in others clinical trials of imagery. * inability to provide informed consent signed. * no social assurance.

Keywords: colorectal cancer recurrence positron emission tomography colorectal cancer with high risk of recurrence stage iii colorectal cancer with high risk of recurrence stage iv t4n0m0 operated in emergency( because of perforation)