[The symptom-diagnosis interval: a possible approximation to the natural history of neoplasms].

In order to assess the influence that age, sex, site of the primary tumor (SPT), the extension and histology may have on the interval first symptom-diagnosis (ISD), 1.149 cases of lung, breast, stomach, colon and rectum cancer registered in the Tumor Registry of the Hospital del Mar (Barcelona) were analyzed. Overall, mean ISD was 5.7 months. 12.7% of women and 5.5% of men (p less than 0.0001) had an ISD greater than one year. Age does not appear to influence ISD in this population (r = 0.014). Among women, the ISD for each SPT was as follows: breast cancer, 9.1 months; rectal cancer, 6.5; stomach, 4.9; colon, 4.7; lung, 2.7. Men's ISD were: rectum, 6.2; stomach, 5.9; colon, 5.7; lung 3.2. Age, sex, SPT, the extension and histology jointly explain only 18% of the ISD variability (multiple r = 0.42 p less than 0.0001). SPT and histology appear to be the strongest predictors, both remaining statistically significant when adjusting for the other four factors. While only breast cancer clearly showed a positive association between ISD and tumor extension, an unexpected inverse relationship was observed in rectal cancer. In some tumors, the ISD may just be an indicator for the rate of tumor growth. ISD data registered in a Tumor Registry can contribute to the study of a part of the natural history of neoplasms. Such analyses are also relevant for studies of secondary prevention and screening programs, access to and quality of care, and psychosocial predictors of the care seeking process.