探討空氣污染暴露與台灣女性乳癌發生與復發之影響

Abstract

背景： 空氣污染是日益嚴重的全球公共衛生問題，其中細懸浮微粒 (PM₂.₅)、二氧化氮 (NO₂) 和臭氧 (O₃) 被認為可能與癌症發生相關。乳癌是全球女性最常見的惡性腫瘤，但亞洲族群中長期暴露於空氣污染與乳癌發生及復發之關聯性尚缺乏明確證據。 研究目的： 本研究旨在探討台灣女性長期暴露於環境中 PM₂.₅、NO₂、O₃ 與乳癌發生及復發風險之關聯，並進一步評估年齡與雌激素受體 (ER) 狀態的潛在修飾效應。 方法： 本研究為醫院基礎病例對照研究，共納入國立台灣大學醫院 233 位乳癌個案及 202 位對照組。採用高解析時空暴露模式估算每位參與者診斷前 3 年、5 年及 8 年的累積平均暴露濃度 (PM₂.₅ μg/m³，NO₂、O₃ ppb)。使用邏輯斯迴歸分析乳癌發生風險，並利用 Cox 比例風險模型分析復發風險，所有模型均調整乳癌已知危險因子。 結果： 診斷前 3 年的 PM₂.₅ 暴露與乳癌風險顯著相關 (每增加 10 μg/m³，勝算比 OR = 1.88，95% CI: 1.21–2.93)，在年齡 ≥50 歲女性中此關聯性一致。對於年齡 <50 歲女性，O₃ 暴露與乳癌風險顯著相關 (OR = 2.39，95% CI: 1.15–4.97)。劑量反應分析顯示 PM₂.₅ 暴露與乳癌風險呈現單調增加趨勢。多污染物模型中 PM₂.₅ 仍為穩定的風險預測因子。在復發分析中，診斷前 5 年的 NO₂ 暴露在年輕女性中顯示增加復發風險 (HR = 1.91，95% CI: 1.14–3.20)，而 PM₂.₅ 和 O₃ 與復發無一致性顯著關聯。 結論： 長期暴露於 PM₂.₅ 和 O₃ 可能增加台灣女性乳癌發生風險，且近期暴露及特定亞群中的影響更為明顯。本研究結果凸顯改善空氣品質的重要性，並需進一步研究釐清污染相關乳癌致癌機制。

Background: Air pollution is a growing global public health issue, with fine particulate matter (PM₂.₅), nitrogen dioxide (NO₂), and ozone (O₃) identified as major pollutants potentially linked to cancer development. While breast cancer is the most common malignancy among women worldwide, evidence on the relationship between long-term air pollution exposure and breast cancer risk and recurrence in Asian populations remains limited. Objectives: This study aimed to investigate the associations between long-term exposure to ambient PM₂.₅, NO₂, and O₃ and the risk of breast cancer incidence and recurrence among Taiwanese women, and to explore potential effect modification by age and estrogen receptor (ER) status. Methods: A hospital-based case-control study was conducted including 233 breast cancer cases and 202 controls recruited from National Taiwan University Hospital. Air pollution exposure was estimated using a high-resolution spatiotemporal model, calculating 3-, 5-, and 8-year cumulative averages for PM₂.₅ (μg/m³), NO₂ (ppb), and O₃ (ppb) prior to diagnosis. Logistic regression was used to estimate odds ratios (ORs) for breast cancer incidence, while Cox proportional hazards models assessed recurrence risks. Models were adjusted for established breast cancer risk factors. Results: Higher short-term (3-year) PM₂.₅ exposure was significantly associated with increased breast cancer risk (OR = 1.88 per 10 μg/m³, 95% CI: 1.21–2.93), with consistent associations in women aged ≥50 years. O₃ was significantly associated with breast cancer risk in younger women (<50 years, OR = 2.39, 95% CI: 1.15–4.97). Dose–response analyses revealed a monotonic trend between PM₂.₅ exposure and breast cancer risk. Multi-pollutant models confirmed PM₂.₅ as a robust predictor. For recurrence, 5-year NO₂ exposure showed a potential increased risk in younger women (HR = 1.91, 95% CI: 1.14–3.20), while PM₂.₅ and O₃ showed no consistent associations. Conclusions: Long-term exposure to ambient PM₂.₅ and O₃ may increase breast cancer risk in Taiwanese women, with stronger effects observed in recent exposures and specific subgroups. These findings highlight the importance of improving air quality and conducting further research to clarify mechanisms underlying pollution-related breast carcinogenesis.