A recent epidemiologic study reported in the New York Times showed a statistical relationship between heartburn and throat cancer; the authors reported a 78% increase in throat cancer in refluxers with heartburn.
I have spent 35 years studying reflux, particularly the silent type, that is, acid reflux occurring without heartburn. Silent refluxers have symptoms such as hoarseness, chronic throat-clearing and cough, difficulty swallowing, post-nasal drip, and asthma-like symptoms. (See also my Silent Reflux post. Indeed, in 1991, I published data from a serries of 31 patients with throat cancer; 84% had documented reflux, but only 33% had heartburn.
Here below is an excerpt from Dropping Acid: The Reflux Diet Cookbook & Cure on the relationship between reflux and throat cancer.
Reflux and Cancer
One of the most frequent questions patients ask is whether reflux can cause cancer. I believe the answer is an emphatic yes. That is part of the reason this book is so concerned about the acidity of today’s typical diet.
We have not yet proven that reflux causes laryngeal and vocal cord cancer, but there is strong circumstantial clinical evidence along with bench research to support it.1,7,9,39,114,119-124 We believe that one can get laryngeal cancer without smoking, but not without the presence of reflux.4,39 This section presents six arguments to support this concept
1. Many patients with laryngeal cancer are non-smokers or ex-smokers. We prospectively studied 50 adult patients with early vocal cord cancer.9 Of them, 44 percent (22/50) were active smokers, 42 percent (21/50) were ex-smokers with a median duration of smoking cessation of eight years, and 14 percent (7/50) were lifetime non-smokers. Using pH monitoring, we found that 68 percent of the patients had reflux, almost twice as many as those who were actually smokers. And remember, in the study group, there were seven lifetime non-smokers.9
2. Some people get recurrent, small, reflux-related vocal cord cancers that are periodically removed with a surgical laser. We’ve seen many such cases over the years. Significantly, almost half of those patients stop making cancer when their reflux is controlled. The same is true for patients with pre-cancers called dysplasia and leukoplakia.1,114
3. When different groups of patients are tested for reflux, including those with cough, sore throat, etc., the highest proportion of those demonstrating reflux are the cancer patients. In 1991, we reported abnormal reflux testing in 84 percent of patients with laryngeal cancer, five of whom were lifetime non-smokers.1
4. We compared the reflux (pH) testing results of smokers and non-smokers and found that smokers had twice as much reflux, both in the esophagus and the throat. Cigarette smoking is specifically associated with relaxation of the upper and lower esophageal valves within two minutes, and reflux episodes occur with two-thirds of cigarettes smoked.55,138
5. Our laboratory has examined the impact of reflux on a cellular level in human patients and in animal models and found tremendous similarities in the larynx between patients who have LPR and patients who have cancer. Of those studies, the most important was an analysis of biopsies for the presence of pepsin within the laryngeal tissue. Pepsin was found in 5 percent (1/20) of normal controls without reflux. On the other hand, 95 percent of LPR patients with reflux into the throat had pepsin in their laryngeal biopsy tissue, and 100 percent (5/5) of laryngeal cancer patients tested had pepsin within the cancerous tissue.39,47,55 In addition, extraordinary landmark experiments in cell biology by Nikki Johnston et al. 42,47,48,51.53,54,124 showed that pepsin up-regulates the genes that cause cancer in a way that suggests that pepsin is actually the cause of laryngeal cancer.124
6. There are similarities between laryngeal cancer and esophageal cancer. We have shown the presence of pepsin in reflux laryngitis by a special staining technique. In addition, using biopsies of patients with reflux and laryngeal cancer, we have shown that both have similar protein profiles except for one stress protein, HSP70.4,39,47-49
As previously mentioned, esophageal cancer is the fastest growing cancer in the United States, up 850% since the 1970s. We are also finding Barrett’s Esophagus, a known reflux-related form of pre-cancer, in approximately 7 percent of our LPR reflux patients.33,44,52 It is striking and significant to note that Barrett’s Esophagus is found just as often in ENT patients with silent reflux (symptoms of coughing and hoarseness) as in GI patients with heartburn.134
In summary, there is clinical and scientific evidence that reflux, mainly pepsin, may cause cancer of the larynx and esophagus.
One of our biggest concerns is that a huge population of Americans is potentially at risk to develop cancer, and that we have no methodology for identifying the most susceptible. As clinicians, we can certainly say that we are seeing increasingly more and more reflux in increasingly younger patients; in our opinion, this is an ominous warning sign.
We regret that we cannot prove all of our assertions and beliefs just yet. However, our data and clinical impressions deserve to be in the public domain so that other researchers and clinicians can investigate the relationships we’ve presented. We believe that diet is the missing link and that our diet may be killing us and it is time for us to aggressively explore these variables and fix them.
By the way, people who are rightfully worried about cancer deserve to be checked. The technology has changed. Doctors can now look inside while patients are awake, comfortable, and without pain, using a technique called transnasal esophagoscopy.29,33,58,134 The idea that you can only be checked for cancer in a special facility and under anesthesia is archaic.
(If you are interested in the references, they may be found in Dropping Acid on pages 177-185.)