Doctors have long encouraged patients with diabetes to exercise regularly to help control their insulin levels and to maintain a healthy weight. Now, breast oncologists at Dana-Farber Cancer Institute in Boston are studying the relationship between exercise, weight, and insulin levels and the risk of breast cancer recurrence.

"We know that women who are overweight at the time of breast cancer diagnosis have a higher risk of recurrence than lean women, but the reasons for this are not clear," says Jennifer Ligibel, MD. "Recent evidence suggests that high insulin levels, which are common in overweight women, may be involved in the increased risk of breast cancer recurrence."

Based on these findings, Ligibel and her colleagues are conducting several studies to examine the potential benefits of regular exercise, diet modification and other weight-control activities in breast cancer survivors. The Active After Cancer Trial explores whether a telephone-based program can motivate patients to start an exercise program after completing treatment for early stage breast cancer. The team is also conducting an exercise study for patients with metastatic breast cancer, designed to determine whether regular exercise can increase energy and physical fitness in women living with advanced disease. Finally, Dana-Farber is participating in the LISA trial, an international study that will examine whether losing weight after breast cancer diagnosis helps to reduce recurrence rates and improve survival in postmenopausal patients with estrogen receptor positive breast cancer.

Ligibel is quick to note that while finding the energy to exercise can be a challenge for many, it can be especially difficult for cancer patients in active treatment. "Unfortunately, chemotherapy decreases a person's energy during treatment, and many people stop exercising completely," she explains. "Often, patients don't return to good exercise patterns after chemotherapy is completed, even if they once had them." This inactivity can lead to weight gain and higher insulin levels, which might also increase the risk of the cancer coming back.

About Breast Cancer

Breast cancer is a malignant (cancerous) tumor that starts from cells of the breast. The disease occurs mostly in women, but men can get breast cancer too. In the U.S., it affects one in eight women. There are many types of breast cancer, though some of them are very rare. Sometimes a breast tumor can be a combination of these types and to have a mixture of invasive and in situ cancer.  The most common types of breast cancer are: 

• Ductal carcinoma in situ (DCIS): This is the most common type of non-invasive breast cancer (85 - 90% of all cases). DCIS means that the cancer is only in the ducts. It has not spread through the walls of the ducts into the tissue of the breast. Nearly all women with cancer at this stage can be cured. Often the best way to find DCIS early is with a mammogram.
• Lobular carcinoma in situ (LCIS): This condition which occurs in approximately 8% of all cases, begins in the milk-making glands but does not go through the wall of the lobules. Although not a true cancer, having LCIS increases a woman's risk of getting cancer later. For this reason, it's important that women with LCIS to follow the screening guidelines for breast cancer.

Less common are: 

• Inflammatory breast cancer (IBC): This uncommon type of invasive breast cancer accounts for about 1% to 3% of all breast cancers. Usually there is no single lump or tumor. Instead, inflammatory breast cancer (IBC) makes the skin of the breast look red and feel warm. It also gives the skin a thick, pitted appearance that looks a lot like an orange peel. Doctors now know that these changes are not caused by inflammation or infection, but by cancer cells blocking lymph vessels in the skin. The breast may become larger, firmer, tender, or itchy. IBC is often mistaken for an infection in its early stages. Because there is no defined lump, it may not appear on a mammogram, which may make it even harder to catch it early. It usually has a higher chance of spreading and a worse outlook than invasive ductal or lobular cancer.
• Paget's disease of the nipple. Paget's disease of the nipple or breast is a rare type of breast cancer, which can occur in women and men. It shows up in and around the nipple, and usually signals the presence of breast cancer beneath the skin. Most cases are found in menopausal women, but can also appear in women that are as young as 20.  Early stages symptoms include redness, scaly and flaky, and  mild irritation of  nipple skin. Advanced stages may include: tingling in nipple skin, very sensitive skin on the nipple, burning or painful nipple skin, ooze or bloody discharge from the nipple (not milk), itchiness that doesn't respond to creams, nipple retraction (pulls into the breast), scaly rash on areola skin, and/or breast lump beneath the affected skin.

Symptoms of breast cancer may include: 

• a lump or a thickening in the breast or in the armpit. Note Most breast lumps are benign (be-nine); that is, they are not cancer. Benign breast tumors are abnormal growths, but they do not spread outside of the breast and they are not life threatening. But some benign breast lumps can increase a woman's risk of getting breast cancer. Most lumps turn out to be caused by fibrocystic (fi-bro-sis-tik) changes. Cysts are fluid-filled sacs. Fibrosis is the formation of scar-like tissue. Such changes can cause breast swelling and pain. The breasts may feel lumpy, and sometimes there is a clear or slightly cloudy nipple discharge.
• a change of size or shape of the mature breast
• fluid (not milk) leaking from the nipple
• a change of size or shape of the nipple
• a change of color or texture of the nipple or the areola, or of the skin of the breast itself (dimples, puckers, rash)
• a discharge from the breast