Introduction: Radiotherapy (+/-chemotherapy) is standard of care for patients
with oropharyngeal cancer (OPC). Late effects of radiotherapy are a key
survivorship issue. Fatigue is well-documented among cancer survivors, however
the prevalence and severity of long-term fatigue in OPC patients remains unclear.
Additionally, neurocognitive outcomes are poorly understood.
Method: Two studies: Radiotherapy for Oropharyngeal Cancer and impact on
Neurocognition (ROC-oN, a mixed methods cross-sectional study) and
Neurocognition in Oropharyngeal Cancer following Radiotherapy (NOC-Rad,
cross-sectional and cross-over components) were undertaken. These
complementary studies evaluated fatigue and neurocognition in patients treated
for OPC with photon or proton radiotherapy. The impact of radiation doses to
cranial structures on fatigue and neurocognitive outcomes were also assessed.
In addition, the feasibility of using an unsupervised online cognitive battery within
real-world and clinical trial settings was evaluated.
Results : In ROC-oN, over 20% of patients, treated on average 6 years ago,
experienced severe fatigue across all domains. Significant differences were
observed between OPC patients and matched controls from the general
population in the domains of mental and general fatigue. Higher level of fatigue
was associated with reduced health-related quality of life, decreased work
productivity and greater mood disturbances. Additionally, 14.8% of patients
reported neurocognitive concerns (NCC) and 33% had impairments in
neurocognitive function (NCF). Attention and working memory were most
affected. No association was identified between radiotherapy doses to the
posterior fossa and fatigue, NCC or NCF. Analysis of the NOC-Rad study is on
going.
Conclusion: This thesis found fatigue to remain a significant issue in patients
treated for OPC several years after radiotherapy (+/- chemotherapy), with a
substantial proportion of survivors experiencing neurocognitive concerns and
impairments. Better monitoring of fatigue and neurocognitive health during follow
up could promote early intervention and improve patient functioning. These
findings will inform supportive care strategies, potentially improving patient quality
of life.
