Complications related to breast cancer usually develop as side effects of treatment methods. For example, side effects may occur with any chemotherapy drug.  Depending on slight differences in regimens, in the drugs themselves, and in the individuals involved, some may experience side effects and others not from the same chemo protocol.

Chemotherapy

The digestive tract and the hair are often involved in a side effect because, like cancer cells, their cells rapidly divide and thus are somewhat damaged as the cancer cells are killed off.  Because nausea and vomiting are such common and prominent side effects of chemotherapy, doctors often will prescribe additional medications to help with such problems. In addition to these visible side effects, low blood counts, which can cause fatigue, easier bruising, or infection, are common because the dividing cells of the bone marrow are also prone to damage by chemotherapy agents.  

In rare instances, chemotherapy can cause heart damage or trigger another cancer such as leukemia. However, the more common long-term complications created by breast cancer and its prevalent treatment method are more gender-specific. Chemotherapy in premenopausal women may damage ovaries so that they stop producing hormones, which may give rise to menopausal symptoms such as vaginal dryness and hot flashes. Periods may stop or become very irregular, making pregnancy virtually impossible. Women who do go into menopause early will also face a higher risk for bone-thinning osteoporosis.

While impossible to predict side effects, the experience of a large majority of women who have undergone chemotherapy is that the side effects subside after treatment is finished.  Nonetheless, a woman’s state of mind may make her side effects feel perhaps more intense than they physically are.  For some, the short-term cognitive issues of concentration and memory loss, known as “chemo-brain, chemo-fog, or chemo-memory,” add to the challenge.

Depression, fear, sadness, or feelings of isolation also may serve to make completion of chemotherapy a difficult time for many women; adjusting back to a “normal” life, while thoughts of a relapse crop up in the not-so-distant background, can be daunting.  Talk therapy with a professional, or regular contact with a family member or friend, during this period is highly advisable.

Radiation and Hormone Therapy

Other treatments, particularly radiation and hormone therapies, can also result in rare, more serious side effects. Side effects of radiation therapy can come on slowly. Over time, common side effects that seemed wholly manageable at first can become debilitating, while more serious—if rarer—complications such as inflamed lung tissue, heart damage, or secondary cancers can emerge.

A possible long-term effect of the lowered estrogen that comes from hormone therapy is a significantly greater risk for osteoporosis. Accordingly, your doctor may monitor your bone mineral density while you're taking the medication. Lower estrogen levels also may lead to vaginal dryness and irritation.

Mastectomy

Another potential complication to note is the psychological effect of having a mastectomy. Some patients may find it discomforting to lose one or both breasts, and may experience depression or anxiety following the surgery. Addressing these feelings, whether through therapy, a support group, or another means, is essential. Some patients may choose to have reconstructive breast surgery following a mastectomy in order to retain the same physical appearance they had prior to the mastectomy, while others may prefer to use breast prostheses to achieve the same effect.