HPV-positive OPSCC patients showed longer time to onset of distant metastases

In patients with oropharyngeal squamous cell carcinoma, distant metastases take significantly longer to develop and have more subsite involvement in HPV-positive patients, according to data presented at the 2014 Multidisciplinary Head and Neck Cancer Symposium.

The study researchers found that in HPV-positive patients, distant metastatic failure generally involves sites not typical of smoking-related head and neck cancer.

Researchers reviewed registry data of 285 patients diagnosed with stage III to IV oropharyngeal squamous cell carcinoma (OPSCC) who were treated with chemoradiotherapy between 2002 and 2013. Of 245 HPV-positive patients and 40 HPV-negative adult patients, the researchers identified failure with distant metastases in 27 among the HPV-positive group and eight patients among the HPV-negative group.

These patients underwent radiation therapy using 3-D conformal radiation therapy or intensity-modulated radiation therapy, with doses ranging from 66 Gy to 79 Gy.

Subsequent chemotherapy was performed with cisplatin, cisplatin/5-FU or cetuximab (Erbitux, ImClone).

Chemotherapy with cisplatin/paclitaxel was administered to one HPV-negative patient, and one patient in each group underwent accompanying chemoradiotherapy after initial resection. The differences between the means of the samples were evaluated using t tests.

Although the rate of distant metastases was found to be similar among HPV-positive and HPV-negative patients with OPSCC (11% vs. 20%), the mean time to onset of distant metastasis after finishing treatment was significantly longer in HPV-positive patients (21.6 months; range, 2.7-79.8) than for those who were HPV-negative (7 months; range, 21-14.4; P=.03).

The lung was the most common site of metastasis in both groups (17 of 27 HPV-positive patients, and five of eight HPV-negative patients), followed by bone metastases (12 of 27 HPV-positive patients, and two of eight HPV-negative patients). On average, HPV-positive patients also had a higher number of metastatic subsites than HPV-negative patients (2 vs. 1.1; P=.026). Seventy-eight percent of the HPV-positive patients had more than one metastatic deposit, and 44% had metastases affecting more than one organ system vs. only 12.5% of HPV patients.

Samuel Trosman

Additionally, the metastases of HPV-positive patients were more likely to spread to less typical metastatic sites, including the liver (n=6), intra-abdominal lymph nodes (n=3), brain (n=2), pleura (n=2) and peritoneum (n=1). Metastasis in the original tumor region was less common in HPV-positive patients, affecting only 15% of these patients vs. 38% of HPV-negative patients.

According to Samuel Trosman, MD, a resident in otolaryngology at the Cleveland Clinic, the finding of late onset of distant metastasis in HPV patients will provide key information for future treatment.

“The late onset of [distant metastasis] in HPV-positive patients is unusual, since the majority of aerodigestive tract malignancies tend to recur within 12 to 18 months of definitive treatment,” Trosman said in a press release. “The multiple and varied distant metastases sites, which can present as distal localized pain, indicate that we may need to be more aggressive in working up suspicions for metastatic disease, and that imaging such as PET/CT scans may be warranted, even several years after treatment.”

For more information:

Trosman S. Abstract #125. Presented at: the Multidisciplinary Head and Neck Cancer Symposium; Feb. 20-22, 2014; Scottsdale, Ariz.

Disclosure: The researchers report no relevant financial disclosures.