Abstract
Introduction:
Human papillomavirus (HPV)-positive and HPV-negative oropharyngeal squamous
cell carcinomas (OPSCCs) are 2 distinct cancers, with HPV-positivity
conferring a better prognosis. Smoking status is a complicating factor for
both patient populations. There have been scattered literature that have
reported on incomplete information regarding the profiles of their patient
population. Details including age and sex distributions, TNM staging,
histology grading, recurrence time and types, death rates, and the direct
causes of deaths have been reported incompletely in the literature. Here,
based on the experience at our university medical centers, we explored all
the details of the important clinical profiles of HPV-negative OPSCC,
HPV-positive OPSCC in smokers and nonsmokers.
Objective:
In this article, we compare detailed clinical profiles of HPV-negative OPSCC
and HPV-positive OPSCC in both smokers and nonsmokers. The clinical profiles
we elucidated here include patients’ age and sex distribution, general
health conditions, histology grading, TNM staging, perineural invasion
(PNI), and lymphovascular invasion (LVI), extracapsular extension (ECE),
recurrence rate and types, death rate, and direct causes. Specifically, we
divided HPV-positive OPSCC into smokers and nonsmokers and compared the
different clinical profiles between these groups to give a better idea of
the complicating role of smoking in the development of HPV-positive
OPSCC.
Method:
All patients with OPSCC at a tertiary care publicly funded county hospital
and a tertiary care university hospital from June 2009-July 2015 were
retrospectively reviewed. The attending physicians were the same at both
hospitals. The primary outcome measure was posttreatment 2-year follow-up
status (locoregional recurrence, distant recurrence, death rate). Other
measures included HPV status based on p16 staining, smoking history, age,
sex, comorbidities, tumor size, nodal and distant metastasis information,
LVI, PNI, ECE, and tumor histology grade.
Results:
A total of 202 patients with OPSCC were identified. They were categorized
into 3 groups: HPV-negative OPSCC group (HPV−), HPV-positive smoker group
(HPV+SMK+), and HPV-positive nonsmoker group (HPV+SMK−). Patients of HPV−
group are older (61.1 ± 11.6 years) than the other groups on average. The
HPV− group has the highest percentage of women (22.7%). The HPV− patients
with OPSCC have more comorbidities than the HPV+SMK+ group and the HPV+SMK−
group, although there is no statistical difference. Grade 2 tumor is the
most common histology grade for HPV− patients with OPSCC, whereas grade 3 is
the most common grade for HPV+SMK+ and HPV+SMK− groups. Both PNI and LVI are
positive at around 40% for all groups without any significant difference,
but ECE is very common for HPV− OPSCC, at 86.7%, which is significantly
higher than that of the HPV+SMK+ and HPV+SMK− groups. There was no
difference of bilateral neck metastases noticed among different groups. For
T staging and N staging, although HPV+SMK− and HPV+SMK+ patients have
relatively lower T stages and higher N stages, there is no significant
difference. HPV+SMK− group has highest TNM stages. All death rates and
recurrence rates increase with time, but the death rate of HPV− group is
about 4 times higher than that of the HPV+SMK+ group and 6 times higher than
that of the HPV+SMK+ group. The major recurrence type of HPV− OPSCC and
HPV+SMK+ is locoregional, and the major recurrence type of HPV+SMK+ is
distant metastasis.
Conclusions:
Our data confirmed that HPV+ OPSCC normally presents with more advanced
stage, however, it has better prognosis. In comparison, HPV− OPSCC presents
at an earlier stage, but the prognosis is worse. Based on their clinical
profiles, we noted that HPV-positive OPSCC cells are more “mobile”; they
metastasize sooner and further. However, HPV-negative OPSCC cells are more
locally infiltrative, leading to more locoregional recurrence. The
HPV-positive patients usually are younger and healthier at diagnosis.
Although HPV-positive OPSCC tend to be histologically higher grades, there
was no statistical difference noticed. Metastatic and recurrent patterns are
very different between HPV-positive and HPV-negative patients, but the death
rate of HPV-negative patients is way higher, and it is mainly due to
locoregional recurrences, which is the major recurrence type for
HPV-negative patients. Of our note, smoking is a complicating factor for
HPV-positive OPSCC, and it makes the death rate, recurrence rate, histology
grade, and TNM staging shift toward HPV-negative OPSCC. How smoking makes
HPV-positive OPSCC behave more like OPSCC-negative OPSCC deserves more
translational research for further elucidation.
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