LBA28 - Prognostic effect of imaging and CEA follow-up in resected colorectal cancer (CRC): Final results and relapse free survival (RFS) - PRODIGE 13 a FFCD phase III trial

Background

Intensive follow-up of patients (pts) after curative surgery for CRC is recommended by various scientific societies. However, the few clinical trials performed are controversial and no survival benefit has been demonstrated to date.

Methods

PRODIGE 13 is a cooperative prospective multicentre controlled phase III trial evaluating by double randomisation the impact of i) intensive radiological monitoring (CT-scan/6m) vs. a standard one (abdominal ultrasound/3m and thoracic radiography/6m) and ii) CEA assessment vs. no, in the follow-up of stage II or III CRC resected for cure. The primary endpoint was 5-year overall survival (OS). The result of the 2^d intermediate analysis: after curative surgery for primary CRC, the addition of CEA and/or CT does not provide any benefit in 5-year OS for the global population of the study. We report here the final results of the RFS.

Results

At all, 75.9% of the pts were < 75 years old (16% rectal, 44% left colon cancers (CC)). Among CC 52% were Stage II (25% adjuvant chemotherapy). With a median follow-up of 7,8 years, cancer recurrence was detected in 22,3% of the pts (39%/61% stage II/III). The recurrence was metastatic in 89.5% and local in 10.5% of the pts. Overall, 5.9% of the pts (95% CI,4.6%-7.2%) were treated for recurrence with curative intent (A: intensive imaging + CEA 37.6%; C: Standard imaging + CEA 50.5%; B: intensive imaging alone 35.1%; D: Standard imaging alone 30.2%; p= 0.0120). The 5-years RFS rates were respectively 71.8%, 74.6%, 69.0% and 67.5% in arm A, B, C and D. Compared with minimum follow-up (D), pts of the arm D had significantly longer RFS, 0,80 ([0.65;0.98]; p= 0.031). The 5-years RFS were respectively 73.2% [70.3;75.8] and 68.2% [65.2;71.0] in CTscan surveillance group vs. not (HR 0.86 [0.75;1]; p=0.052) and 70.4% [67.42; 73.1] and 71.0% [68.1; 73.75] in CEA surveillance vs. not respectively (HR 0.99 [0.86;1.15]; ns).

Conclusions

Among pts who had undergone curative surgery for primary CRC, intensive imaging, but not CEA screening, provided an increased rate of surgical treatment of recurrence with curative intent. There is no survival advantage to any strategy but a trend toward a better 5-years RFS in the CT scan surveillance group versus not.

Clinical trial identification

NCT00995202.

Editorial acknowledgement

Legal entity responsible for the study

FFCD: Federation Francophone de Cancérologie Digestive.

Funding

FFCD: Federation Francophone de Cancérologie Digestive.

Disclosure

C. Lepage: Financial Interests, Personal, Invited Speaker: Ipsen, Amgen, Pierre Fabre; Financial Interests, Personal, Advisory Board: Novartis. All other authors have declared no conflicts of interest.