SCOTTSDALE, ARIZ. – Most patients who are treated for human papillomavirus (HPV)–positive oropharyngeal cancer can safely skip routine imaging after a negative 3-month posttreatment scan, suggest results of a retrospective cohort study reported at the Multidisciplinary Head and Neck Cancer Symposium.
Investigators led by Dr. Jessica M. Frakes of the H. Lee Moffitt Cancer Center in Tampa, Fla., studied 246 patients treated nonsurgically between 2006 and 2014 for nonmetastatic HPV-positive disease.
Dr. Jessica M. Frakes
With a median follow-up of 36 months, all local recurrences and the large majority of regional and distant recurrences were detected from symptoms, physical exam, and the 3-month posttreatment PET-CT imaging, according to data reported in a session and related press briefing.
“Routine imaging is not recommended after posttreatment imaging shows a complete response to treatment, unless the patient presents with symptoms or something else that would warrant imaging,” Dr. Frakes commented. “Follow-up should include history and physical examination with direct visualization.”
Currently, the National Comprehensive Cancer Network advises a one-size-fits-all approach to follow-up that does not consider tumor HPV status, she noted. But reducing surveillance imaging for HPV-positive patients would likely have considerable benefit in terms of less stress and anxiety (provided patients are educated about the safety of clinical follow-up) and lower financial burden for both the patient and the health care system as a whole.
Results additionally showed that the majority of recurrences occurred within the first 6 months, a pattern that was consistent whether or not patients had risk factors for recurrence. The 3-year rate of freedom from local failure exceeded 97%, and only 2% of patients had grade 3 or worse toxicity at their last follow-up.
“Our outcomes are excellent with low rates of permanent toxicity, and we think that this partly is due to the fact that they are treated by specialized multidisciplinary team,” Dr. Frakes commented at the meeting.
Press briefing moderator Dr. Christine Gourin of Johns Hopkins University in Baltimore, commented, “This study is one that’s dear to my heart because I think that we probably do too much posttreatment surveillance, and they are exactly right that the NCCN is fairly vague about when to perform imaging.”
“I can tell you that we have stopped routinely imaging patients after 3 months if the PET is negative, and it’s true that we do pick up recurrences more clinically than we do radiologically,” she added. “And of course the false positives are causing much morbidity.”
Introducing the study, Dr. Frakes commented, “Several retrospective and prospective trials have shown increased survivals and decreased toxicity in patients with HPV-associated oropharynx cancer. As the number of patients and survivors grows, so does the need to determine general time to recurrence and the most effective modes of recurrence detection, thereby guiding our standards for optimal follow-up care.”
All patients studied received definitive radiation therapy, and 85% of them also received concurrent chemotherapy.
The patients had a 3-month posttreatment PET-CT scan, plus physical exams every 3 months in the first year post treatment, every 4 months in the second year, every 6 months in the third through fifth years, and annually thereafter.
Results showed that the 3-year rate of local control was 97.8%, and 100% of the local failures were detected by physical exam, including direct visualization or flexible laryngoscopy.
The rate of regional control was 95.3%, and 89% of cases of regional failure were detected through symptoms or the 3-month posttreatment imaging. Risk factors for regional recurrence included involvement of five or more lymph nodes in the neck and involvement of level 4 (low neck) lymph nodes (P less than .05 for each).
The rate of freedom from distant metastases was 91%, and 71% of cases of distant metastases were detected through symptoms or the 3-month posttreatment imaging. Risk factors for distant metastases included tumor in the lymph nodes measuring greater than 6 cm, involvement of bilateral lymph nodes, involvement of five or more lymph nodes in the neck, and involvement of level 4 lymph nodes (P less than .05 for each).
Overall, 9% of patients experienced grade 3 or worse late toxicity (occurring at 3 months or thereafter), consisting of feeding/gastrostomy tube (G-tube) placement, necrosis or ulcer, and tracheostomy. However, these toxicities had resolved as of the last follow-up in most cases, with a final rate of toxicity of only 2%.
The center follows an aggressive approach to preventing and managing toxicity, noted Dr. Frakes.
“Even when the patients have their G-tube in place, we really do encourage p.o. [oral] intake as much as possible with pain medication. And I think that really does make a big difference for our patients,” she said. “They do meet with a speech pathologist and our nutritionist weekly when they are on treatment.” Patients are also allowed to have the G-tube removed by last follow-up, she added.