Staging and survival of colorectal cancer: are we making progress? The 14-year experience of a Specialized cancer Registry.

Abstract

It is still unclear whether recent advancements in colorectal cancer research have led to an improvement in management and prognosis of the disease. Through the data of a specialized colorectal cancer Registry we aimed at analysing pathological staging and 5-year survival of all patients with malignancies of large bowel diagnosed between 1984 and 1997. Main objective was to ascertain whether or not we are making progress in the control of this common neoplasm. During the 14-year period 1984-97, a total of 2,240 colorectal cancer patients were registered, for a crude incidence rate of 64.5 and 55.2/100,000/year in males and females, respectively Tumours were staged with "Tumour, Node, Metastasis" system, corresponding to Dukes' classification, into four main groups. Survival was assessed with Life Table analysis, and statistical significance--between various subgroups--evaluated with Log-Rank Test. Crude incidence rates of colorectal neoplasms showed minor fluctuations during initial period of registration, increasing sharply after 1990 mainly due to localized (stage I and II) lesions and, to a lesser degree, to stage III tumours. Number of advanced (stage IV and unstaged) malignancies remained virtually stable. When results were expressed as percent of total cases, the fraction of localized lesions increased from 39% in the biennium 1984-5 to 51.6% in 1986-97, and the proportion of advanced tumours fell from 39% to 21.6% (p for trend <0.001). As expected, 5-year survival was significantly (p<0.002) more favourable for individuals diagnosed in 1990-91 than for patients registered in 1984-89. In Northern Italy, incidence rates of colorectal carcinoma are rising. This trend is associated with a sharp increase of newly detected localized lesions and with a significant improvement of overall 5-year survival. The result may be attributed to several concomitant factors, such as: A] wider use of colonoscopy, B) increased education of patients, C) more attention given to symptoms.