Life after breast, prostate, and colon cancer: Primary care’s role

OSTEOPOROSIS

Osteoporosis is a metabolic bone disease characterized by low bone mineral density. As a result, bones become weak and fracture more easily from minor injuries.

Risk factors for osteoporosis include female sex, family history, advanced age, low body weight, low calcium and vitamin D levels, sedentary lifestyle, smoking, and low estrogen levels.¹⁹ Cancer treatment places patients at a greater risk for osteoporosis, particularly for those patients with chemotherapy-induced ovarian failure, those treated with aromatase inhibitors, men receiving androgen-deprivation therapy, and patients on glucocorticoid therapy. The morbidity and mortality associated with bone loss can be prevented with appropriate screening, lifestyle changes, and therapy.²

According to the National Osteoporosis Foundation Guideline for Preventing and Treating Osteoporosis, all men and postmenopausal women age 50 and older should be evaluated clinically for osteoporosis risk to determine the need for bone mineral density testing.^2,19 The US Preventive Services Task Force recommends bone mineral density testing in all women age 65 and older, and for women 60 to 64 who are at high risk for bone loss. ASCO agrees, and further suggests bone mineral density screening for women with breast cancer who have risk factors such as positive family history, body weight less than 70 kg, and prior nontraumatic fracture, as well as for postmenopausal women of any age receiving aromatase inhibitors and for premenopausal women with therapy-induced ovarian failure.¹¹

Androgen deprivation therapy is a mainstay of treatment in recurrent and metastatic prostate cancer. The effect is severe hypogonadism with reductions in serum testosterone levels. Androgen deprivation therapy accelerates bone turnover, decreases bone mineral density, and contributes to fracture risk. The National Comprehensive Cancer Network additionally suggests measuring bone mineral density at baseline for all men receiving androgen deprivation therapy or other medications associated with bone loss, repeating it 1 year after androgen deprivation therapy and then every 2 years, or as clinically indicated.²⁰

The gold standard for measuring bone mineral density is dual-energy x-ray absorptiometry. The World Health Organization FRAX tool uses bone mineral density and several clinical factors to estimate the risk of fracture in the next 10 years, which can help guide therapy. Cancer patients with elevated fracture risk should be evaluated every 2 years. Counseling should be provided to address modifiable risk factors such as smoking, alcohol consumption, physical inactivity, and low calcium and vitamin D intake. Therapy should be strongly considered in patients with a bone mineral density below a T-score of –2.0. ^2,19

Treatment begins with lifestyle modifications such as weight-bearing exercises to improve balance and muscle strength and to prevent falls, and adequate intake of calcium (≥ 1,200 mg daily) and vitamin D (800–1,000 IU daily) for adults age 50 and older. Treatment with bisphosphonates may be required.^2,11,20

NEUROPATHY

Many chemotherapeutic agents can lead to neuropathy and can result in long-term disability in patients. Patients treated with taxane- and platinum-based chemotherapy are at particular risk.

Paclitaxel, used in the treatment of breast, ovarian, and lung cancer, can lead to distal neuropathy. This neuropathy commonly has a stocking-and-glove distribution and is primarily sensory; however, it may have motor and autonomic components. The neuropathy typically lessens when the medication is stopped, although in some patients it can persist and lead to long-term disability.

Treatment can include massage. Medications such as gabapentin and pregabalin can also be used, but randomized controlled trials do not support them, as they predominantly treat the tingling rather than the numbness.¹¹

BLADDER AND BOWEL DYSFUNCTION

Urinary incontinence and dysfunction are frequent complications in prostate cancer survivors. Urinary function should be discussed regularly with patients, addressing quality of the urinary stream, difficulty emptying the bladder, timing, and incontinence.⁴ Urinary incontinence is frequently seen in postprostatectomy patients.

The cornerstone of treating urinary incontinence is determining the cause of the incontinence, whether it is stress or urge incontinence, or both.²¹ For those patients with urge incontinence alone, practitioners can address the problem with a combination of behavior modification, pelvic floor exercises, and anticholinergic medications such as oxybutynin. If the problem stems from difficulty initiating or a slow stream, physicians may consider alpha-blockers.^4,21 If the incontinence is persistent, bothersome, and has components of stress incontinence, the patient should be referred to a urologist for urodynamic testing, cystoscopy, and surgical evaluation for possible placement of a male urethral sling or artificial urinary sphincter.²¹

Colorectal cancer survivors, particularly those who received radiation therapy, are at high risk of bowel dysfunction such as chronic diarrhea and stool incontinence. Patients should be educated about this possible side effect. Symptoms of bowel dysfunction can affect body image and interfere with social functioning and overall quality of life. Patients should be provided with coping tools such as antidiarrheal medication, stool bulking agents, changes in diet, and protective underwear.

CARDIOVASCULAR DISEASE

Evidence suggests that certain types of chemotherapy and radiation therapy increase the risk of cardiovascular disease. Prostate cancer survivors treated with androgen deprivation therapy, particularly those more than 75 years old, are at increased risk of cardiovascular disease and diabetes.²²

It is recommended that men be screened with fasting plasma glucose at baseline and yearly thereafter while receiving androgen deprivation therapy. Lipid panel testing should be done 1 year from initiation of androgen deprivation therapy and then, if results are normal, every 5 years or as clinically warranted. The focus should be on primary prevention with emphasis on smoking cessation, treating hypertension per guidelines, lifestyle modifications, and treatment with aspirin and statins when clinically appropriate.²⁰

Radiation therapy, chemotherapy, and endocrine therapy have all been suggested to lead to cardiotoxicity in breast cancer patients. Anthracycline-based chemotherapies have a well-recognized association with cardiomyopathy. Factors associated with increased risk of anthracycline-induced cardiomyopathy include older age, hypertension, pre-existing coronary artery disease, and previous mediastinal radiation.

Early detection of cardiomyopathy may lead to avoidance of irreversible cardiotoxicity, but there are currently no clear guidelines for cardiac screening in breast cancer survivors. If cardiomyopathy is detected, treatment should include beta-blockers and angiotensin-converting enzyme inhibitors as well as modification of other cardiovascular risk factors.¹¹

A SURVIVORSHIP CARE PLAN

There is life beyond the diagnosis of cancer. As patients are living longer, with an estimated 5-year survival rate of 66.5% of all cancers in the United States, there must be a transition of care from the oncologist to the primary care physician.¹ While the oncologist will remain involved in the initial years of follow-up care, these visits will go from twice a year to once a year, and eventually the patient will make a full transition to care by the primary care physician. The timing of this changeover varies from physician to physician, but the primary care physician is ultimately responsible for the follow-up.

A tool to ease this transition is a survivorship care plan. The goal of a survivorship care plan is to individualize a follow-up plan while keeping in mind the necessary surveillance as outlined. These care plans are created with the patient and oncologist and then brought to the primary care physician. While there is an abundance of literature regarding the creation and initiation of survivorship care plans, the success of these plans is uncertain. Ultimately, the goal of a survivorship care plan is to create open dialogue among the oncologist, the primary care physician, and the patient. This unique patient population requires close follow-up by a multidisciplinary team with the primary care physician serving as the steward.