Does Nantucket really have a higher cancer rate?

Maggie Toole

Assistant editor

(April 16, 2015)

The Massachusetts incidence rates map of all cancer sites from 2007 to 2011.

Cancer is the second most common cause of death in the United States, accounting for one in every four deaths nationwide. On Nantucket, it seems to be even more prevalent.

Some island residents, in fact, believe that the island is experiencing an overwhelming increase in the cancer incidence rate in recent years.

“I honestly have no idea whether or not there has been an increase,” said junior Lizzie Thayer. “I have just seen more people with cancer and heard stories. I don’t know if its because I was younger, but I had never realized that there were so many people with cancer here and I feel like recently I have been seeing a lot more.”

Nantucket has the highest age-adjusted annual cancer incidence rate in Massachusetts at 622.5 cases per 100,000 people, compared to a statewide annual incidence rate of 492.5 cases per 100,000 people. The highest rates of breast cancer incidences in Massachusetts are found in Nantucket and Barnstable County.

There are multiple explanations for the apparent increase in cancer diagnoses on  Nantucket and nationwide. The number of people 65 and older in Massachusetts diagnosed with cancer over a four year period is about nine times higher than the number of people under 65. The average life expectancy of the average U.S. citizen in 2011 was 79 years old, an approximate 10 year increase since 1960. Age is a risk factor of cancer because it is more likely for cellular repair mechanisms to become less effective as people age. Due to the increase in the over 65-year old population, there is an increase in diagnoses.

Changes in the way that cancer is detected and subsequently diagnosed also contributes to the increase in incidence rates. Breast cancer detection has become more advanced due to the use of a variety of methods, the most common being the mammogram.

Nantucket Cottage Hospital surgeon and physician Dr. Time Lepore believes that better diagnosis techniques and an aging population that spends a lot of time in the sun is likely the best explanation for Nantucket’s cancer incidence rates, rather than some unknown environmental factor.

“It used to be palpation, we used to tell women to do a breast self-exam,” said island physician Dr.Tim Lepore. “Probably worthless, all it does is increase anxiety. So then you started getting mammography. Mammography used to pick up one centimeter tumors, now its picking up much smaller tumors. If they are an invasive cancer that’s a real cancer, if they are a duct cell cancer in situ it might not be but they all get lumped together. And then we are doing imaging with MRIs… well the trouble is we don’t know what the hell we are seeing, so then you get an increased number of biopsies that may not be particularly helpful.”

Cancer is the name given to a variety of related diseases all of which are caused by the abnormal division of cells in a certain part of the body. Cancer is a disease caused by the mutation of the genes that regulate cell growth and division.

In Massachusetts, the most commonly diagnosed cancers are breast cancer in women and prostate cancer in men. Both of these rank second in mortality behind bronchus and lung cancer. Cancer rates vary due to a variety of factors including geographical area, racial population, screening rates, and daily behaviors.

This increase in detection has led to an increase in diagnoses, especially diagnosis at a younger age and at an earlier stage, Dr. Lepore said. However, it has also led to overdiagnosis: the diagnosis of a genuine cancer that may not ever develop to the point of causing a problem and would otherwise go undetected.

“We lump even duct cell cancer in situ as a cancer, nobody’s got the guts to watch it over time but it may not be,” said Lepore. Ductal carcinoma in situ (DCIS) is a growth of cells within the breast duct that is non invasive and has not spread outside of the ducts. Diagnosis at this point is called Stage 0 breast cancer and offers an extremely positive prognosis. While it is believed that only 25 percent to 50 percent of women diagnosed with DCIS will develop invasive breast cancer within 10 years, still this is not proven. “I don’t think I see an increased incidence,” said Lepore. “I mean, if you get a 30 year old with a breast cancer that catches everyones attention, but then again you need to know the pathology. Because we perhaps over treat, if you have duct cell cancer in situ and I say to you ‘you have a cancer,’ get the goddamn thing out and then all of the sudden women are having bilateral mastectomies and everything else.” Course of treatment is determined depending on family history and the exact size and location of the tumor. Despite the choice of a less invasive treatment plan, overdiagnosis can lead to lifestyle changes including not breastfeeding or having fewer children.

Prostate cancer diagnosis have also seen an exponential increase over the past few years due to changes in diagnosis techniques and age as a risk factor. It is relatively common for most men 80 years old and older to have cancer cells in their prostate, which without recently developed detection would go untreated and most likely cause no harm. A chemical test using the Prostate Specific Antigen (PSA) is now being more commonly used to diagnose prostate cancer. An elevated PSA can indicate prostate cancer however, the test has not proved extremely accurate because two in three men with elevated PSA’s will not have prostate cancer and one in five men with prostate cancer will have a normal PSA level.

“All of the sudden you’ve changed how you diagnose it,” said Lepore. “It used to be prostate cancer – you diagnosed it with a digital rectal exam, feeling the prostate and you tended to find later disease and more aggressive disease. Nowadays we are testing with PSA testing (Prostate Specific Antigen) and a digital rectal exam, and maybe we are picking up a lot of cancers that wouldn’t have done anything.” Due to the increased detection of cancer in the prostate, the possibility that it could be overdiagnosis remains and often leads to drastic treatments that can devastate a person’s everyday life. Common side effects of prostate cancer treatments can lead to incontinence and impotence in patients.

So Lepore believes that changes in the way that cancer is diagnosed has caused a jump in incidence statistics. This, combined with a feeling of community surrounding recent diagnoses and losses has lead to a fear of possible environmental or geographical factors on Nantucket. However, a statistical increase or significance does not necessarily mean there is a problem, and there are often other factors in play.

“But it’s a change, we are dealing with much smaller tumors,” said Lepore. “These numbers are inflated because of the way we are looking at it.”

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