| disease | Soft Palate Cancer |
Soft palate cancer accounts for 13.5% of primary malignant tumors in the palate. Its disease cause is similar to other malignant tumors in the oropharyngeal region. The most common pathological type is glandular epithelium, followed by squamous epithelium, with malignant melanoma ranking third, and fleshy tumors being rare.
bubble_chart Clinical Manifestations
In the early stages, only mild discomfort in the oropharynx is felt, with symptoms being subtle and easily overlooked. Later, fetid mouth odor, sore throat, and pain during swallowing may occur, radiating to the same side of the face and neck. The use of antibiotics can temporarily alleviate symptoms. In the advanced stage, dysphagia may develop, accompanied by voice changes. Fixation, destruction, or perforation of the soft palate can lead to food reflux into the nasal cavity. Invasion upward or outward into the nasopharynx or parapharyngeal space may cause trismus, difficulty opening the mouth, otitis media, temporal pain, and occasional cranial nerve involvement.
Physical examination may reveal a neoplasm on the lingual surface of the soft palate or the uvula. Almost all squamous cell carcinomas of the soft palate occur on the oral (inferior) surface, while the nasopharyngeal surface rarely develops tumors. Even larger tumors in the nasopharynx seldom invade the nasopharyngeal surface of the soft palate. Early-stage tumor diseases appear red with indistinct borders. White lesions on the soft palate are also common and may represent leukoplakia, carcinoma in situ, or early invasive carcinoma. Multifocal tumor growth on the normal membrane surface is a common feature. Most soft palate cancers are confined to the soft palate or adjacent tonsillar arches at the time of diagnosis, with T-staging as T2
or T3. However, in terms of tumor volume, they are smaller than tumors at the base of the tongue or tonsillar fossa. Mid-advanced stage cancers often present with an ulcerated center, raised edges, or exophytic growth, especially around the uvula. Soft palate tumors first spread to the tonsillar arches and hard palate. Outward extension through the superior constrictor muscle may invade the medial pterygoid muscle and skull base, occasionally involving or compressing cranial nerves within the parapharyngeal space. In advanced stages, the lateral wall of the nasopharynx is often invaded, leading to perforation or ulceration of the soft palate. Lymphatic metastasis first occurs in the subdigastric lymph nodes, followed by spread along the jugular chain. Involvement of the submandibular, submental, or spinal accessory lymph nodes is rare. Approximately 50% of patients have enlarged lymph nodes upon admission, with 16% being bilateral. Clinically palpable lymph nodes may be negative, but about 20% are found to be positive postoperatively. The lymphatic stagnancy of yang rate correlates with T-staging: T1 is 8%, T2 is 36%, and T3 and T4 are 66%.Soft palate cancer is easily visible and may present with superficial ulcers or asymmetrical movement of the soft palate. Palpation often reveals a firm lesion, and a biopsy is required for definitive diagnosis.
bubble_chart Treatment Measures
Very limited lesions can be surgically removed. Due to the multifocal nature of soft palate cancer, limited resection is prone to recurrence at the mucosal margins, so attention should be paid during surgery. Small tumors confined to the uvula can be surgically removed without functional impairment. Radiotherapy has a high cure rate for early intermediate-stage [second-stage] tumors and causes less functional damage, eliminating the need for prostheses or tissue reconstruction. If cervical lymph node metastasis is present, a seasonal epidemic neck dissection should be performed.
2. Surgical Treatment For early-stage tumors (diameter <5mm）手術切除成功率高，併發症少。如果手術時將軟齶全層切除，則需安置假體或重建軟齶以恢復其功能。T1–2 cm), some scholars advocate extensive radical resection, especially for adenoid cystic carcinoma, which tends to invade nerves and spread extensively along the neurovascular bundles of the palate toward the skull base and retrobulbar region. The resection methods are similar to those for tonsillar or tongue base cancers. Post-resection repair methods include posterior pharyngeal mucosal flaps, free skin grafts, and island mucoperiosteal flaps from the greater palatine artery for nasal lining, as well as composite flaps to restore the anatomical shape and physiological function of the soft palate.
3. Combined Treatment Due to the high cure rate of radiotherapy for soft palate cancer and the significant functional injury caused by surgery, radiotherapy was traditionally the primary treatment, with surgery reserved for radiotherapy failures. In recent years, with improvements in surgical resection and reconstruction techniques, there has been a shift toward planned comprehensive treatment involving radical resection followed by radiotherapy.
4. Management of Recurrent Cancer Soft tissue ulcers after radiotherapy for soft palate cancer are rare. If a persistent ulcer occurs, recurrence should be considered. For post-radiotherapy recurrences suitable for surgery, resection can be attempted, but the outcomes are generally poor.
The treatment outcomes for soft palate cancer vary among different studies. Ratzer reported 299 cases of soft palate cancer, with 112 treated by surgery, 139 by radiotherapy, and 22 by combined therapy. The 5-year absolute survival rate was 21%, and the relative survival rate was 30%, with a relative mortality rate of 38% for surgical cases. Weller reported a local recurrence rate of 50% in 30 cases of soft palate cancer treated with radiotherapy. Lindberg reported higher control rates for radiotherapy in soft palate cancer: T1 100%, T2 88%, T3 77%, T4 83%.
Surgical complications include open rhinolalia and nasal regurgitation of food.
