Early PET‐CT in patients with pathological stage III colon cancer may improve their outcome: Results from a large retrospective study

Abstract

BackgroundCurrent staging of pathological stage III colon cancer (CC) is suboptimal; many patients recur despite unremarkable preoperative staging. We previously reported that early postoperative PET‐CT can alter the stage and management of up to 15% of patients with high‐risk stage III CC. This study aimed to determine the role of the test in the general stage III CC population.MethodsA retrospective study of all consecutive patients with stage III CC who underwent early postoperative PET‐CT between 2005 and 2017.ResultsA total of 342 patients, 166 (48.5%) males, median age 66 years (range, 29‐90), were included. Pathological stage was IIIA, IIIB, and IIIC in 18 (5.3%), 257 (75.1%), and 67 (19.6%) patients, respectively. Median number of positive lymph nodes was 2 (range, 0‐32). PET‐CT results modified the management of 46 patients (13.4%): 37 (10.8%) with overt metastatic disease and 9 (2.6%) with a second primary. The 5‐year disease‐free survival for true stage III patients was 81%. The median overall survival for the entire cohort and for true stage III patients was not reached and was 57.2 months for true stage IV. Of the 37 patients found to be metastatic, 14 (37.8%) underwent curative treatments and 9/14 (64.3%) remain disease‐free, with a median follow‐up of 83.8 months. Predictive factors for upstaging following PET‐CT were identified.ConclusionEarly postoperative PET‐CT changed the staging and treatment of 13.4% of stage III CC patients and has the potential for early detection of curable metastatic disease. Outcome results are encouraging. Prospective validation is ongoing.

Role of PET/CT in Evaluation of Postoperative Colorectal Cancer

“…As CRC has a very high recurrence rate and mortality rate, its crucial to use an effective imaging modality for staging, follow up and post-operative evaluation [2]. For surgeons and oncologists CECT used to be the best among multiple imaging modalities for follow up operated colorectal cancer and assessing the respectability of recurrent tumor lesions or residuals, also for further neo-adjuvant chemotherapy, immunotherapy or radiotherapy [4]. Until then, the actual tumor burden could be greatly underestimated.…”

“…Abdominal pain, tenderness, loss of appetite, generalized weakness, weight loss, change in bowel habits, iron deficiency anemia and bleeding per rectum are most common presenting symptoms of CRC [2][3][4]. It's more common between men, alcoholic, smokers and who suffers from chronic bowel diseases as chronic inflammatory bowel disease and FAP (familial adenomatous polyposis) [2] .…”

“…Staging is commonly done by using TNM classifications system depending on depth of tumor invasion, lymph nodes involvement, metastasis to other organs as Primary Tumor size (T), regional lymph Node (N) and distant Metastasis (M) TNM staging is superior than Dukes staging because of greater information that may leads to stage migrations [4].…”

“…Metastasis occurs through different ways: lymphatic, hematogenous, contiguous or transperitoneal spread. Regional lymph nodes, liver, lung and peritoneum are most common sites of metastases from CRC [3][4][5] Fig ( 1-4).…”

Prognostic value of pretreatment F-18 fluorodeoxyglucose PET/CT in colorectal cancer with unresectable metastasis

“…PET/CT is useful in the detection of distant metastasis in CRC patients [13]. It also provides prognostic information in patients with stage III CRC and those who underwent liver metastasectomy [14][15][16]. It is necessary to investigate the relationship between the metabolic aggressiveness of metastatic tumor and the survival of CRC patients with unresectable metastasis.…”