With the end of the year upon us, I thought I'd offer my perspective on the top 5 developments in lung cancer for 2013:

1) Immunotherapy overcame the doubts of almost all skeptics. While past years have included some promising leads in the field, and immune checkpoint inhibitors (anti-PD1 and anti-PDL1) were gaining attention in 2012, 2013 saw reports of sustained responses with nivolumab (anti-PD1 from BMS), as well as exciting new data with the PDL1 inhibitor MPDL3280A from Genentech/Roche, and others as well. While clinical oncologists long considered lung cancer as an infeasible setting for immune-based treatments, 2013 saw the oncology world converge toward profound optimism. Two phase III registration trials of nivolumab recently completed remarkably quickly, a testament to the eagerness of both patients and physician investigators to realize the promise of these agents.

2) Acquired resistance to targeted therapies became a subject of critical concern. After the celebration of the high response rate and prolonged duration of response to specific targeted therapies like EGFR and ALK inhibitors in patients with these driver mutations, patients and their oncologists also remember that nearly all patients eventually progress with acquired resistance to these agents. 2013 saw the remarkable activity of multiple second line ALK inhibitors, as well as some early favorable findings with agents for patients with an EGFR mutation and acquired resistance to a first line EGFR tyrosine kinase inhibitor. Clinicians are increasingly expressing interest in learning how best to manage patients with acquired resistance to these agents and referring patients to places where the most promising trials are being offered.

3)  "Multiplex" testing of a battery of multiple potential driver mutations (hundreds at a time) became widely available. With the Foundation One testing platform from Foundation Medicine, as well as a growing array of genomic sequencing testing options from centers all over, we saw genomic testing in lung cancer pass an inflection point.  I have mixed feelings about the value of testing that has a very high probability of reporting the presence of mutations for which we don't have meaningful clinical evidence to guide treatment, but this certainly represents a profound change in the practice of lung cancer management.

4) 2013 was the year in which squamous cell NSCLC became a lung cancer subtype in which lung cancer researchers became far more excited about treatment possibilities and stopped just wringing our hands about the treatment options NOT available. Immune checkpoint inhibitors appear at least as active in squamous NSCLC as in non-squamous NSCLC. There are several potentially clinically relevant, "targetable" molecular markers in squamous NSCLC identified. And even some chemotherapy agents, such as Abraxane (albumin-bound paclitaxel) appear to potentially be particularly active in squamous NSCLC. We still need to translate most of these observations from the possible to the definite realm, but we saw a clear shift in our perception of the treatment options for squamous NSCLC over the past year.

5)  Initiatives have been introduced to curtail costs. With a new law limiting Medicare recipients to coverage for four PET/CT scans in their lifetime, I expect that we'll see more changes that impose restrictions on costs of drugs and testing that are promote a semblance of value for their cost, with serial PET/CT scans representing a top target of no demonstrated benefit for their cost. That is just the easiest target of care efforts that begin to expect a semblance of value.

A bonus  highlight on the cusp of the list: Growing participation of patients and caregivers. While this has been an ongoing trend, I consider 2013 as a turning point in which ASCO, the International Association for the Study of Lung Cancer (IASLC), cancer centers, and pharma companies came to truly recognize the value of engaging patients and working to give them more tools to seek/find clinical trials, request treatments, and play a far more active role than ever before.

Are there others that you think should crack the top 5 as having changed the landscape of lung cancer and should be prioritized over the ones I've suggested? I'd welcome your thoughts.