How lung metastases travel through airways and what it means for treatment

Lung cancer, particularly adenocarcinoma, may spread through the airway, according to a review article published in the December 2014 issue of the American Journal of Roentgenology. These intrapulmonary aerogenous metastases will have implications for staging, management and prognosis.

“Cumulative evidence suggests that aerogenous spread may exist and is underrecognized,” wrote Anand Gaikwad, MBBS, DMRD, DMRE, DNB, of Southcoast Radiology in Mackay, Australia, and colleagues. “Imaging features are helpful in differentiating possible aerogenous spread of tumor from hematogenous and lymphatic metastases and from synchronous primary tumors.”

After evaluating current literature, Gaikwad and colleagues noted that persistent or growing centrilobular nodules on CT should be considered suspicious for aerogenous spread in patients with primary lung adenocarcinoma. This is especially true for patients with invasive mucinous, papillary and micropapillary subtypes.

“A multidisciplinary approach including clinicians, radiologists, thoracic surgeons, pathologists and geneticists is required to guide diagnosis and treatment in these cases,” wrote the authors. “Genomic profiling may be beneficial for proving monoclonality when aerogenous metastasis is suspected.”

Therapies that target aerogenous dissemination may be beneficial, such as drugs that affect mechanisms involved in cancer cell shedding, anchorage-independent survival and reattachment in distant alveoli.