Social inequalities in male cancer in a metropolis in the Southeast region of Brazil

ABSTRACT OBJECTIVE To analyze inequalities in incidence, mortality, and estimated survival for neoplasms in men according to social vulnerability. METHODS Analysis of cases and deaths of all neoplasms and the five most common in men aged 30 years or older in the city of Campinas (SP), between 2010 and 2014, using data from the Population-Based Cancer Registry (RCBP) and the Mortality Information System (SIM). The areas of residence were grouped into five social vulnerability strata (SVS) using São Paulo Social Vulnerability Index. For each SVS, age-standardized incidence and mortality rates were calculated. A five-year survival proxy was calculated by complementing the ratio of the mortality rate to the incidence rate. Inequalities between strata were measured by the ratios between rates, the relative inequality index (RII) and the angular inequality index (AII). RESULTS RII revealed that the incidence of all neoplasms (0.66, 95%CI 0.62–0.69) and colorectal and lung cancers were lower among the most socially vulnerable, who presented a higher incidence of stomach and oral cavity cancer. Mortality rates for stomach, oral cavity, prostate and all types of cancer were higher in the most vulnerable segments, with no differences in mortality for colorectal and lung cancer. Survival was lower in the most social vulnerable stratum for all types of cancer studied. AII showed excess cases in the least vulnerable and deaths in the most vulnerable. Social inequalities were different depending on the tumor location and the indicator analyzed. CONCLUSION There is a trend of reversal of inequalities between incidence-mortality and incidence-survival, and the most social vulnerable segment presents lower survival rates for the types of cancer, pointing to the existence of inequality in access to early diagnosis and effective and timely treatment.

摘要
目的：基于社会脆弱性分层，分析男性肿瘤的发病率、死亡率及估算生存率的不平等状况。
方法：本研究纳入巴西坎皮纳斯市（圣保罗州）2010至2014年30岁及以上男性的所有肿瘤及5种最常见肿瘤的病例与死亡数据，数据来源于人群肿瘤登记库（Population-Based Cancer Registry, RCBP）与死亡信息系统（Mortality Information System, SIM）。采用圣保罗社会脆弱性指数（São Paulo Social Vulnerability Index）将研究对象的居住区域划分为5个社会脆弱性层级（social vulnerability strata, SVS）。针对每个层级，计算年龄标化发病率与死亡率；通过死亡率与发病率的比值估算5年生存率。采用发病率比值、相对不平等指数（Relative Inequality Index, RII）及角度不平等指数（Angular Inequality Index, AII）衡量各层级间的不平等程度。
结果：相对不平等指数（RII）结果显示，社会脆弱性最高组的所有肿瘤总体发病率（0.66，95%CI 0.62–0.69）、结直肠癌与肺癌的发病率均更低；而胃癌与口腔癌的发病率在该组更高。胃癌、口腔癌、前列腺癌及所有肿瘤的死亡率在社会脆弱性最高组显著升高，结直肠癌与肺癌的死亡率则无组间差异。本研究纳入的所有肿瘤类型中，社会脆弱性最高组的生存率均更低。角度不平等指数（AII）显示，低社会脆弱性层级存在超额病例数，而高社会脆弱性层级存在超额死亡数。社会不平等程度因肿瘤部位及分析指标的不同而存在差异。
结论：发病率与死亡率、发病率与生存率之间的不平等状况存在逆转趋势；社会脆弱性最高组的各类肿瘤生存率均更低，提示在早期诊断以及及时获取有效治疗方面存在不平等现象。