Association between diet and lung cancer location

Our plain-English summary of Association between diet and lung cancer location, by B.W. Lee, J.C. Wain, K.T. Kelsey, et al (American Journal of Respiratory and Critical Care Medicine, 1998).

The study

• Authors: B.W. Lee, J.C. Wain, K.T. Kelsey, J.K. Wiencke, D.C. Christiani
• Journal: American Journal of Respiratory and Critical Care Medicine
• Published: 1998;158(4):1197-203
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Lung cancers occur more commonly in the upper lobes than in the lower lobes, but its pathophysiologic basis is not well understood. Because numerous studies have reported a consistent inverse relationship between lung cancer risk and intake of certain vegetables and fruits, we hypothesized that the balance between diet-derived protective substances delivered via the circulation and cigarette-derived carcinogenic substances delivered via the airways would be less favorable in the upper lobes compared with the lower lobes, hence accounting for the upper lobe predominance of tumors among smokers. Thus, we examined the association between diet and tumor location in 328 patients with lung cancer. The ratio of upper to lower lobe tumors was 2.5:1.0. In univariate analysis, age, height, weight, sex, race, family history of cancer, education level, tumor histology, calories consumed per day, and intake of animal fat did not differ significantly between patients with upper versus lower lobe tumors. Predictors of tumor location in univariate analysis were family history of lung cancer; smoking history; history of asbestos exposure; and intakes of yellow-orange vegetables, alpha-carotene, beta-carotene, and vitamins A, C, and E. In multivariable logistic regression analysis, the independent predictors of upper lobe tumor location were family history of lung cancer (p = 0.03), history of asbestos exposure (p = 0.02), less intake of yellow-orange vegetables (p < 0.04), and less intake of vitamin E (p = 0.05). Our results show a strong inverse association between upper lobe location of lung cancer and intake of yellow-orange vegetables and vitamin E.

In plain English

This study used data from a hospital case-control study to look at 328 patients with newly diagnosed primary lung cancer at Massachusetts General Hospital between December 1992 and August 1996. Almost all had tumors that could be removed by surgery. The authors compared 235 patients with upper lobe tumors against 93 with lower lobe tumors (a group that included the right middle lobe). They used questionnaires on diet, smoking and work, including an asbestos exposure index based on job type and years worked. Significant asbestos exposure was reported by 14.5% of upper lobe patients versus 4.4% of lower lobe patients. In a combined statistical model, four factors were each linked with upper lobe location: asbestos exposure (odds ratio 5.69, 95% confidence interval 1.28 to 25.22), family history of lung cancer, lower intake of yellow-orange vegetables, and lower intake of vitamin E. The authors concluded that lung cancer location may be determined, in part, by diet. They noted that the diet reports were open to recall bias and that the findings apply mainly to non-small-cell lung cancer.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Analysis of lung cancer cases from a hospital-based case-control study, comparing patients with upper lobe tumors against patients with lower lobe tumors
• Who was studied: 328 patients with newly diagnosed primary lung cancer seen by the thoracic surgery service at Massachusetts General Hospital, Boston, December 1, 1992 to August 15, 1996. Almost all had surgically resectable tumors. These were the 328 of 456 enrolled cases with complete dietary, occupational and smoking histories.
• Exposure: Diet was measured with a 126-item food frequency questionnaire. Smoking history was also recorded. Asbestos exposure was measured with an index that weighted years of exposure by calendar period and by job intensity: for example, shipbuilding and insulation work scored highest, and brake mechanic and carpentry work scored lowest. A score above 20 counted as significant exposure. No fiber types were named.
• Main results:
  • 235 patients (71.6%) had upper lobe tumors and 93 (28.4%) had lower lobe tumors, an upper to lower ratio of 2.5 to 1.0.
  • Significant asbestos exposure was more common among patients with upper lobe tumors (14.5%) than among those with lower lobe tumors (4.4%).
  • In the multivariable model, history of asbestos exposure was associated with upper lobe tumor location: odds ratio 5.69 (95% confidence interval 1.28 to 25.22), p equal to 0.02.
  • Family history of lung cancer was more common in upper lobe patients (24.8%) than in lower lobe patients (12.5%). In the multivariable model its odds ratio for upper lobe location was 2.36 (95% confidence interval 1.06 to 5.24).
  • Patients with upper lobe tumors ate fewer yellow-orange vegetables on average (0.49 servings per day) than patients with lower lobe tumors (0.68 servings per day).
  • Comparing the highest with the lowest third of yellow-orange vegetable intake, the odds ratio of upper lobe location was 0.45 unadjusted and 0.47 after stratifying by smoking.
  • Mean vitamin E intake was 63 mg per day in upper lobe patients and 124 mg per day in lower lobe patients. Unlike yellow-orange vegetables, vitamin E showed no steady step-by-step relationship with tumor location.
  • Dark green vegetables, fruits and vitamin C were not significant predictors of tumor location in the multivariable analysis.
• The authors' conclusion: The authors concluded that their results suggest lung cancer location may be determined, in part, by dietary factors.
• Limitations the authors state:
  • Almost all patients had operable tumors (stage I, II or IIIA).
  • Fewer than 3% had small-cell lung cancer, so the authors said the findings apply mainly to non-small-cell lung cancers.
  • Diet was self-reported on a questionnaire and so was open to recall bias.
  • Only the 328 of 456 enrolled cases with complete histories were analyzed. The authors considered whether this caused selection bias.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer.

Medical terms in this study, explained in our Lexicon: Lung Cancer, Carcinogenic, Histology, Asbestos Exposure.

Related studies

• Association of cigarette smoking and asbestos exposure with location and histology of lung cancer — B.W. Lee, J.C. Wain, et al. (1998)
• Carotenoid actions and their relation to health and disease — N.I. Krinsky, E.J. Johnson (2005)
• Dietary intake and the risk of malignant mesothelioma — J.E. Muscat, M. Huncharek (1996)
• Diet and other risk factors for laryngeal cancer in Shanghai, China — W. Zheng, W.J. Blot, et al. (1992)
• Protective dietary factors and lung cancer — E.T. Fontham (1990)
• The role of intervention studies in ascertaining the contribution of dietary factors in lung cancer. The Seattle chemoprevention trial of retinoids in asbestos-exposed workers — G.S. Omenn, G.E. Goodman, et al. (1988)

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