Marriage, cohabitation and incidence trends of invasive penile squamous cell carcinoma in Denmark 1978–2010

Abstract

Few population-based studies have investigated the relation between living arrangements and risk of invasive penile squamous cell carcinoma (iP-SCC). Using long-term national cancer registry data in Denmark we examined incidence trends of iP-SCC. Furthermore, we examined the relation between marital status, cohabitation status and risk of iP-SCC using hazard ratios (HRs) with 95% confidence intervals (CIs) obtained in Cox proportional hazards regression analyses as our measure of relative risk. Overall, 1,292 cases of iP-SCC were identified during 65.6 million person-years of observation between 1978 and 2010. During this period, the WHO world age-standardized incidence remained relatively stable (p-trend 5 0.41) with an average incidence of 1.05 cases per 100,000 person-years. When compared to married men, those who were unmarried (HR 1.37; 95% CI: 1.13-1.66), divorced (HR 1.49; 95% CI: 1.24-1.79) or widowed (HR 1.36; 95% CI: 1.13-1.63) were at increased risk of iP-SCC. Regarding cohabitation status, single-living men were at increased risk of iP-SCC compared to men in opposite-sex cohabitation (HR 1.43; 95% CI: 1.26-1.62). Risk increased with increasing numbers of prior opposite-sex (p-trend 5 0.02) and same-sex (p-trend < 0.001) cohabitations. In conclusion, single-living Danish men and men who are not currently married are at increased risk of iP-SCC, and the risk increases with the number of prior cohabitations, perhaps reflecting less stable sexual relations in these subgroups.Invasive penile cancers, of which up to 95% are penile squamous cell carcinomas (iP-SCC), are rare malignancies that occur mainly among elderly men at a mean age around 60 years. 1 In industrialized countries the age-standardized incidence of penile cancer is generally around or less than 1 per 100,000 person-years. 2-4 However, the annual incidence varies considerably worldwide from around 4 per 100,000 in countries such as Uganda and Brazil, 4-6 while it is close to zero among Israeli Jews. 4 In Denmark, the incidence declined from 1.15 to 0.82 per 100,000 person-years between 1943 and 1990. 7 Several population-based studies have evaluated the trends in penile cancer incidence over time. Most studies have reported a declining incidence, 5-11 while some have indicated a stable incidence over time. 12,13 A recent study from the Netherlands even suggested a slightly increasing trend of penile cancer incidence between 1989 and 2006, 14 but this was explained by a significant increase in penile carcinoma in situ over time, whereas the incidence of invasive penile cancer remained stable. A recent Danish study 15 also reported an overall increase in the incidence of penile cancer in recent years. However, concerns regarding methodological problems in that study have been raised, such as the use of supplementary data sources that were incomplete before the mid-1990's, thus contributing to the impression of an increasing trend. 16 Risk factors for penile cancer include phimosis, 17-21 tobacco use 17,18,20,21 and multiple sex partners. 1...

Socioeconomic factors and penile cancer risk and mortality; a population‐based study

“…A similar association was found in a USA register‐based study . Furthermore, a Danish population‐based study encompassing 1292 men with penile cancer found that all categories of single men (unmarried, divorced, widowers) were at an increased risk of invasive penile cancer . This also applies to other malignancies, e.g.…”

A urologist’s contemporary guide to penile cancer

“…The number of lifetime partners consistently proved to be correlated with a higher risk of pSCC both in a case-control study based on telephone interviews and in a population-based registry study [11,14].…”

“…In a population-based study, Ulff-Møller et al found that men who were unmarried, divorced or widowed were at increased risk of invasive penile squamous cell carcinoma (pSCC) [11]. The number of lifetime partners consistently proved to be correlated with a higher risk of pSCC both in a case-control study based on telephone interviews and in a population-based registry study [11,14].…”

“…Compared to the observed skyrocketing trend in prostate cancer in recent decades, no dramatic changes have been reported in the incidence of penile cancer. Most studies on penile cancer find a stable or only slightly varying incidence depending on the registry studied and the methods applied [4,5,[7][8][9][10][11][12].…”

The Danish National Penile Cancer Quality database

“…The incidence in Denmark is estimated to be 0.8/100,000 population/year, and the mean age at diagnosis is 65 years 4. Data on ∼65 patients are entered into the database each year, which has currently accumulated to more than 200 entries.…”