Anti-osteoporosis drugs bisphosphonates boost esophageal cancer risk

Taking anti-osteoporosis drugs, known as oral bisphosphonates, may double the risk of esophageal cancer, according to a new U.K. case-control study released in British Medical Journal.

Dr. Jane Green and colleagues from the University of Oxford's Cancer Epidemiology Unit found people who took oral bisphosphonates for bone disease over a five-year period or were given more than 10 prescriptions were twice as likely to have esophageal cancer, or cancer of the gullet, as those who did not use or used lesser amounts of the drug. But the drugs were not correlated with colorectal cancer risk.

The researchers came to the conclusion after analyzing data from the UK General Practice Research Database involving 2,954 patients with esophageal cancer, 2,018 patients with stomach cancer and 10,641 patients with colorectal cancer, whose cancers were detected at the age of 40 or older between 1995 and 2005.

Oral bisphosphonates may cause other health problems. 

Another study in the Aug 2010 issue of Clinical Orthopaedics and Related Research suggests that taking the anti-osteoporosis medications for a prolonged period may boost risk of fractures.

Isaacs J.D. and colleagues from The St George and Sutherland Hospital Orthopaedic Departments, in Sydney, Australia found the association between bisphosphonate use and femoral insufficiency fractures after evaluating 100 patients with low-energy femoral shaft fractures before and after taking bisphosphonates.

They found all of 41 patients who received bisphosphonate therapy had underlying femoral insufficiency fractures while none of those 21 patients with low-energy femoral fractures prior to the osteoporosis drugs becoming available had insufficiency fractures.

The findings suggest that use of bisphosphonates boosts the risk of femoral insufficiency fractures.

Esophageal cancer is expected to be diagnosed in 16,640 Americans in 2010 and the disease will kill about 14,500 men and women in the country in the same year, according to the National Cancer Institute.

Many factors may affect the risk of esophageal cancer, which includes squamous cell carcinoma and adenocarcinoma.

Factors affecting risk of Squamous Cell Carcinoma

Tobacco and alcohol

Studies show that people using tobacco were 2.4 times as likely to develop esophageal cancer as the general population. In those who consumed alcoholic beverages, the risk of esophageal cancer was 2 to 7 times higher compared to the general population. Alcohol abuse was also found to boost the risk.

Dietary factors

Diets with high amounts of cruciferous  vegetables like cabbage, broccoli and cauliflower and green and yellow vegetables and fruits were associated with reduced risk of esophageal cancer.

Aspirin and non-steroidal anti-inflammatory drugs

Aspirin or non-steroidal anti-inflammatory drug, or NSAID, use apparently reduced the risk of dying or developing esophageal cancer by 43 percent. 

But one should not use such drugs to prevent esophageal cancer because evidence is strong that NSAID use leads to upper gastrointestinal bleeding and serious cardiovascular events such as myocardial infarction, heart failure, hemorrhagic stroke, and renal impairment.

Helicobacter pylori infection and gastric atrophy

Infection of helicobacter pylori - the bacterium that can cause stomach cancer - and gastric atrophy may increase the risk of esophageal squamous cell carcinoma by 110 percent.

Factors affecting Adenocarcinoma of the Esophagus

Gastroesophageal reflux/Barrett esophagus

This condition was associated with adenocarcinoma. But it is unknown whether removal of gastroesophageal reflux by surgical or medical means would cut the risk of esophageal adenocarcinoma.

Those who like to know the brand names of the oral anti-osteoporosis drugs bisphosphonates may find a report here interesting.

By David Liu and editing by Rachel Stockton