Radiation treatment after breast cancer: not optional

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The Question: I have a friend who has just had a lumpectomy and sentinel lymph node biopsy for a small invasive lobular breast cancer. She has not yet met with the surgeon for her final report but knows that radiation to her breast will be one of the next steps in her treatment. She is quite reluctant to have radiation treatment and wonders about the risk of recurrence if she does not have radiation. Can you refer us to information that would help her with this decision – like what the likelihood of recurrence is without radiation and the long-term effects of radiation? She would like to have time to review this information before meeting with the radiation oncologist.

The Answer: Cancer treatment is an area where strict adherence to the rules is paramount if you want to ensure the best possible outcome – in this case, cure is the aim so we should ensure not failing our goal. Radiation treatment after lumpectomy is not an option but part of a package. There is a risk of the cancer returning if you do not undergo it.

“Many patients ask, if they can choose receiving radiation or not,” said Jean-Philippe Pignol, a radiation oncologist at Sunnybrook and professor of radiation oncology at University of Toronto. And in this case, “cancer treatment is not like choosing options when you buy a car. It is more a black or white thing and not receiving the appropriate treatment is a serious decision.”

Cancer patients such as your friend – who have undergone breast-conserving surgery – require radiation treatment. That’s because no matter how good a surgeon is at removing the tumor and surrounding tissue, there is always chance a couple of cancer cells – invisible to the naked eye – were missed.

Perhaps the easiest way of looking at it is to look at how much risk your friend is willing to accept. Without radiation treatment, the risk of the breast cancer recurring in five years is up to 30 per cent. In other words, the odds are almost one in three that the cancer will return in five years if she does not undergo radiation. When breast cancer returns, it is metastatic half of the time, which means it has spread to surrounding tissue, organs or bones, making cure impossible. The goals of care at that point will be lengthening survival as long as possible.

Compare that to patients who undergo radiation following breast cancer: their risk of recurrence over five years is about five per cent. In other words, they have a one in 20 chance of the cancer returning over five years. After five years, patients are often considered cured of the disease and if cancer returns after that period of time it is considered a new primary.

Theoretically, your friend is onto something: 70% of the patients may not recur after limited surgery there are likely breast cancer patients who do not require radiation whose survival would not be impacted but as of today, oncologists have no way of determining who these patients are.

“It’s rare that they would say maybe no radiation is necessary,” said Dr. Pignol.

There is no question radiation therapy represents a significant burden in terms of time and psychic energy: typically, patients are required to come every day, five days a week up to five weeks.

“Daily radiation is very disruptive,” said Dr. Pignol in an interview. “It has a great impact on patients’ lives and nobody is very pleased to go every day at a cancer center. It can be extremely draining, physically and psychologically.”

There are other side effects of radiation besides boredom, including burning on the skin – roughly 30 per cent of patients will experience it, but this side effect disappears typically after a week or two.

There have also been concerns that those who have radiation to the left breast may have a higher chance of coronary artery disease and myocardial infarction than those whose right breast is irradiated.

But according to Dr. Pignol, this seems untrue today as technological advances – in the form of CT scans – helps doctors better see what they are actually treating.

Though there is an additional radiation exposure, the chance of developing a secondary cancer due to the radiation treatment is almost undetectable.

Recognizing the arduous length of time for radiation treatment is a barrier to patients across Canada – especially those in remote areas who must travel to urban centers – doctors are studying ways to provide it in a compressed, shortened period of time. Even today, some patients can obtain radiation at certain Canadian centers over several weeks.

“We’re working on solutions,” said Dr. Pignol. “And since we cannot select who should receive radiation and those who should not, the best thing to do is to simplify the radiation treatment and make it more patient friendly.”

To that end, doctors are looking to see if they can compress that five-week radiation treatment, to shorter periods, including treatment in a single session using implanted radioactive seeds or delivery of radiation during surgery.

Lisa Priest is Sunnybrook’s Manager of Community Engagement & Patient Navigation. Her blog Personal Health Navigator provides advice and answers questions from patients and their families, relying heavily on medical and health experts.  Her blog is reprinted on healthydebate.ca with the kind permission of Sunnybrook Health Sciences Centre.  Send questions to AskLisa@sunnybrook.ca.