Background

The number of studies addressing per- and polyfluoroalkyl substances (PFAS) and cancer is increasing. Many communities have had water contaminated by PFAS, and cancer is one of the important community concerns related to PFAS exposure.

Objectives

We critically reviewed the evidence relating to PFAS and cancer from an epidemiologic standpoint to highlight directions for future research that would be the most likely to meaningfully increase knowledge.

Methods

We conducted a search in PubMed for studies of cancer and PFAS (through 9/20/2020). We identified epidemiologic studies that provided a quantitative estimate for some measure of the association between PFAS and cancer. Here, we review that literature, including several aspects of epidemiologic study design that impact the usefulness of study results.

Results

We identified 16 cohort (or case-cohort) studies, 10 case-control studies (4 nested within cohorts and 6 non-nested), 1 cross sectional study and 1 ecologic study. The cancer sites with the most evidence of an association with PFAS are testicular and kidney cancer. There are also some suggestions in a few studies of an association with prostate cancer, but the data are inconsistent.

Discussion

Each study's design has strengths and limitations. Weaknesses in study design and methods can, in some cases, lead to questionable associations, but in other cases can make it more difficult to detect true associations, if they are present. Overall, the evidence for an association between cancer and PFAS remains sparse. A variety of studies with different strengths and weaknesses can be helpful to clarify associations between PFAS and cancer. Long term follow-up of large-sized cohorts with large exposure contrasts are most likely to be informative.

中文翻译：

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PFAS 和癌症，流行病学证据的范围审查

背景

针对全氟和多氟烷基物质 (PFAS) 和癌症的研究数量正在增加。许多社区的水被 PFAS 污染，癌症是与 PFAS 接触相关的重要社区问题之一。

目标

我们从流行病学的角度批判性地审查了与 PFAS 和癌症相关的证据，以突出未来研究的方向，这些方向最有可能有意义地增加知识。

方法

我们在 PubMed 中进行了癌症和 PFAS 研究的搜索（截至 2020 年 9 月 20 日）。我们确定了流行病学研究，这些研究为 PFAS 与癌症之间的关联提供了定量估计。在这里，我们回顾了这些文献，包括影响研究结果有用性的流行病学研究设计的几个方面。

结果

我们确定了 16 项队列（或病例队列）研究、10 项病例对照研究（4 项嵌套在队列中，6 项非嵌套）、1 项横断面研究和 1 项生态研究。与 PFAS 相关的证据最多的癌症部位是睾丸癌和肾癌。在一些与前列腺癌相关的研究中也有一些建议，但数据不一致。

讨论

每项研究的设计都有优点和局限性。在某些情况下，研究设计和方法的缺陷可能会导致有问题的关联，但在其他情况下，如果存在真正的关联，则更难检测到真正的关联。总体而言，癌症与 PFAS 之间关联的证据仍然很少。各种具有不同优势和劣势的研究有助于阐明 PFAS 与癌症之间的关联。具有大暴露对比的大型队列的长期随访最有可能提供信息。