The American Joint Committee on Cancer (AJCC) has announced a new edition of its staging manual for head and neck cancers. The revisions include sweeping changes in the classifications of some head and neck cancers and are scheduled to go into effect on January 1, 2018.
Explore This IssueJune 2017
Dennis Kraus, MD, director of the Center for Head and Neck Oncology at the New York Head and Neck Institute in New York City, reviewed the update during a panel session at the Annual Meeting of the Triological Society. The changes are most dramatic in mucosal melanoma, oropharyngeal cancer, cancer with an unknown primary, and cancer of the oral cavity, he said.
The panel discussion also touched on robotic surgery and on the role of checkpoint inhibitors in head and neck cancer.
Changes to Cancer Staging
A main driver of the changes to the AJCC system was the goal to make staging a better tool for communicating with patients about their survival prospects, he said. “The concept is that we want to give any individual the actual likelihood of survival for their cancer,” he said. Those drafting the changes also wanted to refine the staging so that there would be a similar number of patients in each group, or roughly 25% in each of the four stages, he said.
Another goal in making the changes is to distinguish each subgroup’s survival rates from those above and below it, he said. The changes also strive for worldwide acceptance and are meant to be applicable regardless of the resources of a center or provider, Dr. Kraus added.
Oropharyngeal cancer: Dr. Kraus said this is the category that has been updated the most. “One of the most notable changes—not just in the head and neck changes, but literally in this entire 600-page tome—are the changes that have been made in oropharyx cancer,” he said. Under the new system, only patients with metastatic disease will be considered stage IV. That’s because, when looking at three-year overall survival, stages I through III were grouped together fairly tightly, with “almost no statistical significance,” he said.
He added that, under the previous edition of the staging manual, the majority of patients were classified as having stage IV disease. “There’s poor balance, there’s poor hazard discrimination, and this was a must-fix for the current group,” he said. “We’ve made the obvious changes. We’ve separated oropharynx from hypopharynx. We have separate staging both for clinical and pathologic staging. And, interestingly, it’s very similar to nasopharynx disease, which has some overlap.”
There were no changes to the T (the size and location of the primary tumor) category, but many changes to the N (nodal) category. A clinical N1 designation will mean one or more ipsilateral lymph nodes, none greater than 6 cm; a clinical N2 will be contralateral or bilateral lymph nodes, none more than 6 cm; and clinical N3 will be lymph nodes larger than 6 cm.
Pathological N1 will be metastasis in four or fewer lymph nodes, and pathological N2 will be metastasis in more than four lymph nodes. There will be no pathological N3 category.
Dr. Kraus acknowledged this might make for tricky conversations between patients and clinicians, who will have to “try to tell [patients] that what is stage IV disease as we sit here in 2017 really is stage I or stage II. And it does create some challenges.”
He added that smoking was not included in the staging system, despite the evidence suggesting its effect on risk because the data were just not strong enough yet to build it in. He anticipated it would be incorporated in the next edition.
Mucosal melanoma: Dr. Kraus said the main change here was an acknowledgement of the poor outcome that most patients tend to have with this disease. There will no longer be a T1 or T2 classification, only T3, T4a, and T4b, because the outcomes are just too dire, he said. Eliminating those levels is “one of the rare times this has ever occurred in the AJCC,” he added.
“Because of the universally poor outcome, I think this an appropriate amendment. Even when you are stage 3a, you have anticipated survival that’s approximately 40%, and as you get into the 4c you ultimately approach zero over time,” Dr. Kraus said. “In spite of our efforts, this population of patients continues to do poorly.”
Unknown primary that is p16-negative: Dr. Kraus pointed out that most unknown primaries end up being positive for p16 protein, associated with HPV positivity, but that this staging involves only the p16-negative variety. A notable change in this area is that the pathologic extranodal extension (ENE) is broken into two segments: “micro” ENE with extension of no more than 2 mm, and “major” ENE with extension of more than 2 mm. Pathological ENE will increase the N stage by one level from the previous system, he said.
Oral cavity cancer: The depth of invasion has been incorporated into the update, and will now increase the T category by one step for every 5 mm of invasion, Dr. Kraus said.
Dr. Kraus hopes the staging changes will improve care. “I think this will have a significant impact on our patients [and] a significant impact upon where we decide to both intensify and de-intensify patient care.”
In another segment of the panel session, J. Scott Magnuson, MD, the chief medical officer of the Florida Hospital Nicholson Center in Celebration, Fla., said the onward march continues in robotic surgery, fueled by new technology geared toward augmenting the knowledge and skill of human experts; new financial models in which price is aligned with value and that promote technology that will lower the cost of treatment rather than increase it; and new roles for surgeons in which this technology could help boost the patient–provider ratio.
Dr. Magnuson said that most of the robotic surgery technology now in use is at Level 1, which allows the operator to keep continuous control of the system while the robot helps in some way. However, there are already robots made, although these are not yet commercially available, that are at a Level 3. At this level, the operator selects and approves a plan, and the robot performs the procedure automatically under close supervision. One such robot can suture after the surgeon sets it up, he added.
Another robot in the design phase is being devised to reach a Level 4—it is even able to make decisions, although it’s still under close supervision. “The ‘surgical cockpit’ is really the future for us,” Dr. Magnuson said. “If we’re to compare this to the airline industry and what pilots have— they’ve gone from manual control to computer controls to where the plane is flown automatically.”
Ravi Uppalurri, MD, PhD, director of head and neck surgical oncology at the Dana Farber Cancer Institute in Boston, discussed the evolving role of checkpoint inhibition in the treatment of head and neck cancer, including the use of these therapies prior to surgery.
The therapies—which include nivolumab and pembrolizumab—have been shown to overcome the way in which a tumor can blunt the body’s immune response to cancer. They essentially “release the brakes” in the immune system’s fight against the tumor and have been shown to have lasting responses.
Some patients have had dramatic success with these types of therapy, with complete eradication of cancer in the neck, he said. “Ultimately, these kinds of vignettes really need to be confirmed with larger trials,” he added. “But I think these kinds of neoadjuvant approaches are really going to change how we manage our patients.”
Thomas R. Collins is a freelance medical writer based in Florida.