Despite the undeniable medical advances achieved in recent decades, cancer remains one of the main causes of mortality. It is thus extremely important to make every effort to discover new risk factors for this disease, particularly ones that can be treated or modified. Various pathophysiologic pathways have been postulated as possible causes of cancer or its increased aggressiveness, and also of greater resistance to antitumoral treatment, in the presence of both intermittent hypoxia and sleep fragmentation (both inherent to sleep apnea). Thus far, these biological hypotheses have been supported by various experimental studies in animals. Meanwhile, recent human studies drawing on preexisting databases have observed an increase in cancer incidence and mortality in patients with a greater severity of sleep-disordered breathing. However, the methodologic limitations of these studies (which are mostly retrospective and lack any measurement of direct markers of intermittent hypoxia or sleep fragmentation) highlight the need for controlled, prospective studies that would provide stronger scientific evidence regarding the existence of this association and its main characteristics, as well as explore its nature and origin in greater depth. The great epidemiologic impact of both cancer and sleep apnea and the potential for clinical treatment make this field of research an exciting challenge.

Clinical practice guidelines (CPGs) have been developed to provide health-care practitioners with the best possible evidence, but the quality of these CPGs varies greatly.

A 54-year-old man who had undergone bilateral sequential lung transplant for idiopathic pulmonary fibrosis was admitted to the hospital for further evaluation of an abnormal abdominal CT scan. Three months previously a gastrojejunostomy tube had been placed after he was found to have evidence of silent aspiration with oral intake. At a recent clinic visit, he denied abdominal pain or problems with the feeding tube. He described frequent diarrhea since placement of the feeding tube.

An 80-year-old man presented because of superficial head trauma sustained after falling from bed. On review of systems, he reported worsening dyspnea on exertion, nonproductive cough, and weight loss over the preceding 2 to 3 months. There was no report of chest pain or leg swelling. He had a past medical history of hypertension, coronary artery disease, subclinical hypothyroidism, and renal cell carcinoma treated with partial right nephrectomy approximately 1 year before this presentation. Two months earlier he had been evaluated in the dermatology clinic for painful, dystrophic fingernails. At that time he was diagnosed with acropachy with onycholysis and suspected superinfection, and after failing to improve with vinegar soaks and topical antimicrobials, he underwent surgical nail removal on the second and fourth digits of the right hand. Histological examination of the operative specimens revealed dystrophic nails with negative fungal stains. His medications included levothyroxine, hydrochlorothiazide, and clopidogrel. He had never smoked and had done clerical work until retirement. He was originally from Colombia.

A 28-year-old man of Japanese descent presented to the ED with a 2-month history of dry cough, shortness of breath, and weakness. He did not complain of fever, chest pain, or abdominal symptoms, and had no history of smoking. The patient's medical history was significant for an episode of ulcerative colitis 6 years previously after presenting with bloody diarrhea, stomach pain, fever, weight loss, and bilateral episcleritis. He had been treated consecutively with mesalazine, azathioprine, infliximab, golimumab, and adalimumab. Concomitant respiratory symptoms had been present during 2 flare-ups of severe ulcerative colitis disease activity and were successfully treated with a course of oral prednisone.

To our knowledge, we report the first case of sarcoid-like granulomatous reaction induced by nivolumab, a fully human IgG4 anti-programmed death 1 (PD-1) immune checkpoint inhibitor antibody. A 57-year-old man was treated with nivolumab 3 mg/kg for 2 weeks for a desmoplastic melanoma stage III American Joint Commission on Cancer, with no BRAF, NRAS, and cKit mutations. At 10 months, although melanoma complete response was achieved, he developed sarcoid-like granulomatous reaction in the mediastinal lymph node and skin, which resumed after nivolumab arrest. Melanoma did not relapse after 12 months of follow-up. Considering the recently demonstrated role of activated PD-1/PDL-1 axis in sarcoidosis, granulomatous reaction in the patient seems to be a paradoxical reaction, but similar observations have been reported with ipilimumab, another immune checkpoint inhibitor. Sarcoid-like granulomatous reaction during immunotherapy treatment could be a manifestation of cell-mediated immunity induced by these drugs. Impact of granulomatous reaction induced by immune checkpoint inhibitor on melanoma progression is not known and requires further study. Melanoma patients treated by immunotherapy (anti-cytotoxic T-lymphocyte-associated protein-4/anti-PD-1) should be considered for developing sarcoid-like granulomatous reaction that must not be confused with tumor progression.

Baclofen, a gamma-aminobutyric acid-B agonist with muscle-relaxant properties, is widely used in patients with severe spasticity. In animals, baclofen has been shown to decrease respiratory drive. In humans, however, use of baclofen at the standard dose did not significantly impair sleep-disordered breathing in a susceptible population of snorers. Recently, there has been increasing interest in the role of baclofen for the treatment of alcohol dependence. We describe severe central sleep apnea (CSA) in four patients with none of the conditions commonly associated with CSA who were receiving chronic baclofen therapy for alcohol withdrawal. In one patient, baclofen withdrawal was associated with a complete resolution of CSA. Three patients were treated by adaptive servo-ventilation while continuing their treatment with baclofen. Given the increasing number of patients receiving baclofen for alcohol withdrawal treatment, physicians should be aware that these patients might be affected by severe CSA. Future studies are required to determine the mechanisms, prevalence, and treatment modalities of sleep-disordered breathing associated with baclofen usage.