AboutMichael Dean Expertise Can answer
General information on the causes of cancer and cancer prevention.
Information on current cancer research and breakthroughs.
The genetics of cancer
The risk of smoking for lung cancer and other cancers, as well as SIDS, heart disease, and vision loss.
Cannot answer
Specific medical questions
Experience Cancer Researcher for over 20 years
Author of the book "Empty Cribs-The impact of smoking on child health" www.artsciencepub.com.
Author of over 200 scientific articles on cancer, genetics and human disease.
Multiple interviews in print, TV and radio media.
Organizations American Association for Cancer Research
American Association of Human Genetics
Publications Scientific journals (Science, Nature, NE Journal Medicine, etc.)
Scientific American, Discovery Medicine, Nature Reviews in Cancer
Education/Credentials PhD. in Biochemistry from Boston University School of Medicine
Awards and Honors Young Investigator award-American Association of Cancer Research
Question QUESTION: Hello Michael, I have written you before regarding this subject. To give you some back story, my mother was a smoker and diagnosed with non-small cell adenocarcinoma at the age of 47. She passed a little over a year later at the age of 48. You had told me that my and my sisters risk was pretty low since we did not smoke. I found an article that I read and scared me all over again. I will attach it here, but can you help me decipher this?? Does this mean that we are more danger than originally thought?? What do these numbers mean??
Also, can you tell me what would constitute a "family history?" Would there have to be more than 2 family members to qualify as a significant history?? My great-great uncle had it and passed I think before I was born or shortly after so I know that he was in his 50's or 60's respectivley.
Here is the article. Please help me.
STUDY OBJECTIVES: To clarify the possibility of a hereditary predisposition to lung cancer, we investigated the association between a family history of lung cancer and subsequent risk of lung cancer in a large-scale, population-based cohort study. DESIGN: We investigated 102,255 middle-aged and older Japanese subjects (48,834 men and 53,421 women) with 13-year follow-up. A total of 791 cases of lung cancer were newly diagnosed during the follow-up period. RESULTS: A family history of lung cancer in a first-degree relative was associated with a significantly increased risk of lung cancer (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.31 to 2.88). The association was stronger in women than in men (HR, 2.65; 95% CI, 1.40 to 5.01 and HR, 1.69; 95% CI, 1.03 to 2.78, respectively), and in never-smokers than in current smokers (HR, 2.48; 95% CI, 1.27 to 4.84 and HR, 1.73; 95% CI, 0.99 to 3.00, respectively). In addition, family history was more strongly associated with the risk of squamous cell carcinoma than with other histologic types (HR, 2.79; 95% CI, 1.37 to 5.68), while no clear increase in risk was observed in adenocarcinoma and small cell carcinoma. A family history of overall cancer was not associated with an increased risk of lung cancer. CONCLUSIONS: These results suggest that those with a family history of lung cancer are more likely to acquire lung cancer themselves.
ANSWER: Dear Cori,
Thanks for writing back. This is an interesting study.
They are saying that a family history, increases your risk of lung cancer. A first degree relative is someone one step away (parents and siblings). They say that this risk is 2-3 times higher.
That may sound like a lot, but the lung cancer risk of a non-smoker is very low. So a 2-3 fold increase still means that your risk is very low. It is something to mention to your doctor, and like all of us, you should avoid secondhand smoke.
You can lower risk overall of cancer (and many other diseases) a lot, by eating right, exercising, maintaining a normal weight, getting regular checkups and cancer screening, checking your skin and doing breast self exams. Some studies point to vitamin D as an agent to lower cancer risk, including lung.
So I really would not worry and focus on positive things that you can do to improve health.
I hope this helps,
Michael Dean, Ph.D.
Author "Empty Cribs-The Impact of Smoking on Child Health"
http//www.artsciencepub.com
---------- FOLLOW-UP ----------
QUESTION: I guess what I want to know that I did not ask in the previous follow up is this:
1. - Is it more likley that her cancer was sporadic due to her smoking or is it more likley given the type that it was that it was more in the "hereditary" group??
2. - Would her doctor have mentioned that to us if it were concerning that it was a genetic cancer?? I know that you are not a doctor, but your background in cancer research must have driven over this subject??
Thank you.
Answer Cori,
The influence of genes on lung cancer is very low compared to smoking. So yes your mothers adenocarcinoma was most likely sporadic, and due to her smoking. There are no genetic conditions that give a high risk of lung cancer. (there are some such rare conditions for breast, colon, ovarian, kidney).
Your great uncle would be a second degree relative to your mom (assuming he was her fathers brother or mothers brother) and so that influence would be small.
Lung cancer was an extremely rare disease 120 years ago, before cigarettes became popular.
Yes if your doctor thought there was a genetic cause of your mothers and great uncles cancers, he/she should have discussed that with you. But since they were smokers, that is the most likely answer, and as I said, there are no known genetic conditions that cause lung cancer.
I hope this helps more. There are interesting and important questions.
