Welch H G, Schwartz L M, Woloshin S
VA Outcomes Group (111B), Department of Veterans Affairs Medical Center, White River Junction, VT 05009, USA.
JAMA. 2000 Jun 14;283(22):2975-8. doi: 10.1001/jama.283.22.2975.
Increased 5-year survival for cancer patients is generally inferred to mean that cancer treatment has improved and that fewer patients die of cancer. Increased 5-year survival, however, may also reflect changes in diagnosis: finding more people with early-stage cancer, including some who would never have become symptomatic from their cancer.
To determine the relationship over time between 5-year cancer survival and 2 other measures of cancer burden, mortality and incidence.
Using population-based statistics reported by the National Cancer Institute Surveillance, Epidemiology, and End Results Program, we calculated the change in 5-year survival from 1950 to 1995 for the 20 most common solid tumor types. Using the tumor as the unit of analysis, we correlated changes in 5-year survival with changes in mortality and incidence.
The association between changes in 5-year survival and changes in mortality and incidence measured using simple correlation coefficients (Pearson and Spearman).
From 1950 to 1995, there was an increase in 5-year survival for each of the 20 tumor types. The absolute increase in 5-year survival ranged from 3% (pancreatic cancer) to 50% (prostate cancer). During the same period, mortality rates declined for 12 types of cancer and increased for the remaining 8 types. There was little correlation between the change in 5-year survival for a specific tumor and the change in tumor-related mortality (Pearson r=.00; Spearman r=-.07). On the other hand, the change in 5-year survival was positively correlated with the change in the tumor incidence rate (Pearson r=+. 49; Spearman r=+.37).
Although 5-year survival is a valid measure for comparing cancer therapies in a randomized trial, our analysis shows that changes in 5-year survival over time bear little relationship to changes in cancer mortality. Instead, they appear primarily related to changing patterns of diagnosis. JAMA. 2000.
癌症患者5年生存率的提高通常被推断意味着癌症治疗有所改善，死于癌症的患者减少。然而，5年生存率的提高也可能反映出诊断方面的变化：发现更多早期癌症患者，包括一些原本不会因癌症出现症状的患者。
确定5年癌症生存率与另外两项癌症负担指标（死亡率和发病率）随时间的关系。
利用美国国家癌症研究所监测、流行病学和最终结果计划报告的基于人群的统计数据，我们计算了1950年至1995年20种最常见实体瘤类型的5年生存率变化。以肿瘤为分析单位，我们将5年生存率的变化与死亡率和发病率的变化进行关联。
使用简单相关系数（Pearson和Spearman）衡量5年生存率变化与死亡率和发病率变化之间的关联。
1950年至1995年，20种肿瘤类型的5年生存率均有所提高。5年生存率的绝对提高幅度从3%（胰腺癌）到50%（前列腺癌）不等。同一时期，12种癌症的死亡率下降，其余8种癌症的死亡率上升。特定肿瘤的5年生存率变化与肿瘤相关死亡率变化之间几乎没有相关性（Pearson相关系数r = 0.00；Spearman相关系数r = -0.07）。另一方面，5年生存率的变化与肿瘤发病率的变化呈正相关（Pearson相关系数r = +0.49；Spearman相关系数r = +0.37）。
尽管5年生存率是在随机试验中比较癌症治疗方法的有效指标，但我们的分析表明，5年生存率随时间的变化与癌症死亡率的变化关系不大。相反，它们似乎主要与诊断模式变化有关。《美国医学会杂志》，2000年。
