Metachronous carcinomas in colorectum and its clinicopathological significance.

PURPOSE: The study was designed to examine the significance of colorectal metachronous carcinoma in a large cohort of patients. METHODS: Over a mean follow-up period of 10 years, the clinicopathological features, microsatellite instability (MSI) and clinical follow-up of 56 patients with metachronous colorectal carcinoma were analysed. RESULTS: The prevalence of metachronous colorectal carcinoma was 2.1 %. The metachronous colorectal carcinomas appeared between 7 and 246 months (mean = 66 months) after surgical resection of the index colorectal carcinomas. Thirty-six per cent (n = 20) of the metachronous carcinoma occurred more than 5 years after the operation of the index carcinoma. Of the 56 patients, 20 % (n = 11) of the metachronous colorectal carcinomas were mucinous adenocarcinoma. Cancers detected in the secondary operations (metachronous colorectal carcinomas), when compared with the primary index cancers, were smaller, showed higher proportions of mucinous adenocarcinoma and more often located in the proximal colon. Patients with metachronous colorectal cancers had higher prevalence of mucinous adenocarcinoma, loss of staining for MSI markers and better survival rates than other patients with colorectal cancers. CONCLUSIONS: Patients with metachronous colorectal carcinomas have characteristic features, and attention to these features is important for better management of this group of cancer.

Sun exposure and the incidence of melanocytic nevi in young Australian children.

The number of melanocytic nevi (MN) is an important risk factor for cutaneous melanoma. The present study further investigated the relationship between sun exposure, the incidence of MN, and the prevalence of large acquired MN (>or=5 mm). A cohort of 479 preschool children born in Townsville, Australia was examined for MN in 1991 and a year later. Sun exposure was assessed by questionnaire. The erythemally effective dose of solar UV radiation was estimated from questionnaire data combined with local UV biometry. Almost all (97.7%) children had acquired new MN (median, 12), with a median incidence rate of 11.0 per year (interquartile range, 7.0-16.5). Total number of hours of sun exposure during follow-up (P = 0.034) and tendency to burn (P = 0.028) were independent risk factors for MN incidence. Sunburn experience during follow-up failed to reach significance when adjusted for tendency to burn. Lifetime number of sunburns (P < 0.001) and the severity of sunburns experienced during follow-up (P < 0.001) were significantly related to the presence of large acquired MN at follow-up. Reducing the total number of hours of sun exposure is particularly relevant in sun-sensitive children and may restrain the development of MN, whereas avoiding sunburn in young children might prevent large MN, subsequently reducing the risk of melanoma.

Geographical variation of incidence of cutaneous melanoma in Queensland.

OBJECTIVE: The study investigated geographical differences and time trends of incidence rate and body site distribution of cutaneous melanoma in Queensland. DESIGN: Analysis of data recorded by Queensland Cancer Registry. PATIENTS: Analysis included 34 021 patients with invasive and 10 710 patients with in situ melanoma diagnosed between 1982 and 2002. MAIN OUTCOME MEASURES: Age-standardised incidence rates (world standard population) per 100 000 inhabitants of cutaneous melanoma and annual percentage change (APC). RESULTS: Yearly age-standardised incidence rates of invasive melanoma averaged over the 21 years of observation were highest in the south-eastern part of the state, notably in the statistical division Moreton for men (54.2) and in Fitzroy for women (51.4). Inland divisions had on average lower rates than coastal areas. For both men and women, age-standardised incidence rates of invasive and of in situ melanoma increased between 1982 and 2002 for Queensland as a whole and for almost all its statistical divisions. For invasive cancer, the increase was strongest for Moreton (APC men: 5.4%; women: 4.5%; P < 0.001, respectively). APCs were higher for in situ melanoma compared with invasive melanoma for all statistical divisions and both genders. In both genders, the increase in invasive rates was most pronounced for the trunk (APC men: 3.2%, P = 0.040; women: 2.3%; P = 0.306). CONCLUSIONS: The south-eastern corner of Queensland endured the main burden of melanoma. Behavioural and lifestyle choices might create the observed differences between statistical divisions. The increase in trunk melanomas is discussed with respect to aetiology.