Respiratory Muscle Function and Exercise Capacity in a Stage 4 Head and Neck Cancer Patient Receiving Chemoradiotherapy

INTRODUCTION

Head-and-neck cancer is a broad term that consists of epithelial malignancies that arise in the paranasal sinuses, nasal cavity, oral cavity, pharynx, and larynx. Most head-and-neck cancers are squamous cell carcinomas of the head and neck.[1] It is the 6^th most common type of cancer that represents about 6% of all cases and accounts for an estimated 650,000 new cancer cases and 350,000 cancer deaths worldwide every year.

Clinically, the disease presents with change in voice, swelling, or persistent sore throat that does not heal over a period of time, tongue pain, difficulty swallowing solid food, mouth ulcer, sudden unexplained weight loss, fatigue, cough, occasional breathlessness, and certain pulmonary complications that could be due to chronic smoking history or immunity-compromised complications of long-duration treatment side effect.[2] Based on signs and symptoms, the disease is diagnosed by physical examination, blood and urine tests, endoscopy, biopsy fine-needle aspiration cytology, X-ray/barium swallow, ultrasound, computed tomography (CT), magnetic resonance imaging, and positron emission tomography–CT.

Treatment options for head-and-neck cancer depend on the type and stage of cancer, side effects, patients' preference, and overall health. Surgical management in the initial stages of the disease uses laser technology, excision, lymph node dissection or neck dissection, and reconstructive surgery. In the advanced stage of the disease, the treatment protocol is more inclined toward radiation, chemotherapy, or a combination of both.[3] Although chemoradiation is a fundamental choice of treatment, patients present with a various number of treatment-related side effects that lead to long-term disabilities such as generalized peripheral muscle weakness, muscle mass loss, poor quality of life (QOL), decrease in functional physical activity, and respiratory complications.[4] In such cases, physical therapy in view of multimodal exercises to enhance the strength, respiratory functions, and QOL play a vital role in patients' course of the disease being treated.[5]

SUBJECTS AND METHODS

The patient is a 60-year-old male who was apparently asymptomatic until 6 months back when he started complaining of pain during swallowing, which was insidious in onset and gradually progressive in nature. The pain aggravated while swallowing more of solids than liquids with no relieving factors. There was no associated history of change in voice, swelling in the neck, regurgitation, and ear pain, loss of weight, or appetite. Furthermore, there was no history of difficulty in breathing, cough, or any recent upper respiratory infection. With the above complaints, he visited the hospital where detailed history and initial investigations were done on the basis of clinical presentation. Blood and urine tests showed Hb – 14.0, total lymphocyte count – 6600, platelets – 2.67 lakhs, blood urea – 29, and serum creatinine – 1.00. X-ray showed normal parenchyma with no infiltration. Assessment suggested supraglottic growth for evaluation for which he was posted for direct laryngoscopy and biopsy. Following the biopsy, the patient was diagnosed of Stage 4 Cancer Supraglottis and was planned for chemoradiation therapy from March 2019. Detailed medical history was taken which stated that he was hypertensive for 10 years and controlled with tablet amlodipine 5 mg (1-2-2). With normal vitals and normal body mass index, a radiation therapy dose of 70 Gy/35 fractions for 7 weeks was started from March 28, 2019. The patient underwent 35 fractions of radiation and 7 cycles of chemotherapy–injection kemoplat 65 mg in 250 ml NS IV for 1 h till the date of the report. Before the start of chemoradiation therapy, the patient was evaluated for respiratory pressures [Table 1] (maximal inspiratory pressure [MIP] and maximal expiratory pressure [MEP]) and diaphragm thickness and mobility using the ultrasound [Table 2]. A 6-min walk test (6MWT) was also conducted to test his functional capacity at baseline and 3 weeks [Table 3]. After 3 and 7 weeks of chemoradiation management, he was again evaluated for the above outcomes to see for any significant changes in respiratory muscle function or exercise capacity during and at the end of treatment.

RESULTS

Interpretation: (I) Diaphragm ultrasound–diaphragm mobility from baseline (2.7 cm) to 3 weeks and 7 weeks (2 cm) showed a significant decrease of 0.7 cm while the thickness remained the same. (II) Respiratory pressures showed a decline of almost 15–20 cm H₂O in both MIP and MEP from baseline to 3 weeks and a decline of 2–5 cm H₂O from 3 weeks to 7 weeks. (III) A 30-m decline was noted in 6-min walk distance for exercise capacity at 3 weeks as compared to baseline.

DISCUSSION

This case study evaluated the impact of treatment-related side effects on the respiratory system and the functional capacity of a patient with head-and-neck cancer undergoing chemoradiation. Many of the previous studies showed significant changes in diaphragm and respiratory functions. However, these studies concentrated on the changes mainly seen postoperatively. A study conducted by Santana et al. in 2014 evaluated inspiratory muscle strength and diaphragm function in a head-and-neck cancer patient immediately post neck dissection, after 1 month, and after 3 months. In this study, they noted a decrease in the respiratory strength and diaphragm mobility immediately after the surgery, but a decrease in diaphragm thickness was seen only after 3 months postoperatively, and the reason they stated was decreased physical activity and protein-calorie intake.[6] Several studies show evidence on side effects of chemoradiation on peripheral muscle weakness, muscle mass loss, cachexia, and fatigue.[4] However, no studies show evidence on respiratory system complications due to chemoradiation in head-and-neck cancer patients even though many of these patients tend to lean into pulmonary complications clinically that deteriorate their respiratory function and functional capacity to perform basic activities of daily living s as well as overcome the poor QOL. In this case study, we noted a decrease in function of the major muscle of respiration, its mobility, respiratory pressures, and minimal decrease in functional capacity with 6MWT which may contribute to the deterioration of the patients' condition over the treatment period. Hence, this study could provide a need for early respiratory care and prevention of respiratory complications associated with chemoradiation. Further research with a higher level of evidence and a larger sample size can help plan a structured protocol in pulmonary care in these patients to improve their respiratory muscle function and exercise capacity.

CONCLUSION

This case report shows that there was decrease in the respiratory muscle function and exercise capacity in a head and neck cancer patient receiving concomitant chemo radiation.