Cancers of the palate

Data on right is from U Florida study below, showing local control of soft palate cancer with radiation therapy treatment

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Int J Radiat Oncol Biol Phys 2001 Jun 1;50(2):359-66

SOFT PALATE CANCER — Early stage soft palate cancers may behave in a relatively indolent manner and remain in the early stages. Most patients do not have palpable cervical lymph nodes, but there is a significant correlation between tumor thickness and nodal disease. In one study of 39 patients, for example, none of the 24 lesions ≤2.86 mm were associated with cervical adenopathy, while all of the 15 lesions ≥3.12 mm had palpable adenopathy . Patients with thicker lesions also had a worse prognosis.

Patients with early soft palate cancer are usually treated with radiotherapy delivered as external beam radiotherapy (EBRT), interstitial brachytherapy, or both. The use of prophylactic neck irradiation or observation remains controversial. The neck should be electively treated if the risk of occult metastatic disease exceeds 15 percent, given the poor prognosis with observation in this setting. If surgery is chosen for the primary tumor, then we recommend elective surgical treatment of the neck since even patients with early lesions and a negative neck are at risk for lymph node metastases. If EBRT is chosen for the primary tumor, the neck should be electively irradiated.

Radiotherapy — The initial volume includes the entire soft palate and adjacent pillars and the upper neck; EBRT is given using opposed lateral fields. Some institutions have suggested that, for well-lateralized lesions, elective nodal radiotherapy can be confined to the ipsilateral neck. The boost volume can be treated by EBRT, intraoral cone (performed prior to EBRT) or, in selected cases, interstitial brachytherapy.

For T1 lesions, we administer 50 Gy in 25 fractions by EBRT plus 16 Gy in eight fractions boost by EBRT or 15 Gy in six fractions boost by intraoral cone.

For T2 lesions, we administer 50 Gy in 25 fractions by EBRT plus 20 Gy in 10 fractions boost by EBRT.

Some centers advocate the use of interstitial brachytherapy with iridium 192 in conjunction with EBRT for small soft palate lesions since this spares the major salivary glands and reduces the risk of xerostomia. The EBRT dose is usually 50 Gy in 25 fractions, followed by a 15 to 30 Gy single plane implant.

Results — External beam radiotherapy produces local control in approximately 87 to 92 of T1 lesions and 70 to 75 percent of T2 lesions . The five-year survival in one study of 75 patients was 83, 78, and 38 percent, respectively, with stage I, II, and III disease, respectively.

Adverse sequelae including soft tissue necrosis are uncommon, occurring in less than 10 percent of patients. Severe complications, principally osteonecrosis of the mandible requiring surgical resection, occur in less than 5 percent

Similar outcomes have been described in patients with soft palate cancer treated with EBRT and brachytherapy . Estimated five year values for disease-free and overall survival have been 43 and 57 percent, respectively.

The duration of therapy may be important with combination therapy. In one series of 370 patients with soft palate and tonsillar carcinoma (two-thirds of whom had T1 or T2 disease), the total duration of irradiation and the delay between external irradiation and brachytherapy were significant prognostic factors for local control and overall survival . It was suggested that the overall duration should not be more than seven weeks: five weeks of external irradiation plus a delay of 12 to 15 days, but not more than 20 days, between external therapy and brachytherapy. At five years, patients treated with the shorter duration had higher rates of both local control (85 versus 73 percent, p = 0.01) and overall survival (59 versus 38 percent, p<0.001).

Novel schedules of fractionated high-dose-rate and pulsed-dose-rate brachytherapy, which simulate classical continuous low-dose brachytherapy, have been developed and used with some success in patients with squamous cell carcinoma of the soft palate and tonsillar fossa. In one study of patients with predominantly T2 and T3 lesions at these sites, the local relapse-free survival was approximately 90 percent, exceeding the value of 61 percent in historical controls treated with EBRT

**Cancer of the Soft Palate**
Stage	Conventional XRT	Hyperfractionated XRT
T1	81 - 100%	100%
T2	65 - 88%	100%
T3	45 - 77%	60%
T4	25 - 35%

The present study presents the experience at the University of Florida with treatment of unselected patients with carcinomas of the soft
palate with radiation therapy (RT) alone or followed by planned neck dissection.RT doses delivered with megavoltage equipment ranged from 45 to 80 Gy (median 62.4) at 1.5 to 2.7 Gy (median 2) per fraction for patients treated with once-daily fractionation and from 50.4 to 81.6 Gy (median 76.8) at 1.2 Gy per fraction for patients treated with twice-daily fractionation. Local control rates at 5 years were 86% for T1, 91% for T2, 67% for T3, and 36% for T4 carcinomas. Nodal control rates at 5 years were 86% for N0, 76% for N1, 61% for N2, and 67% for N3 carcinomas. Overall treatment time and planned neck dissection significantly affected nodal control in multivariate analysis. Ultimate local-regional control rates at 5 years were 90% for Stage I, 92% for Stage II, 84% for Stage III, and 60% for Stage IV disease. Overall treatment time and planned neck dissection significantly affected ultimate local-regional control in multivariate analysis. The overall survival rate at 5 years was 42% for all patients. The cause-specific survival rate at 5 years was 70% for all patients. Overall treatment time and planned neck dissection significantly affectedcause-specific survival in multivariate analysis.
Conclusion: For limited carcinomas of the soft palate, RT (alone or followed by planned neck dissection) results in relatively high local-regional controland survival rates. For advanced carcinomas of the soft palate, local-regional control and survival rates are relatively low and local-regional recurrence rates are substantial. Advanced carcinomas of the soft palate may be better treated with RT and concomitant chemotherapy.
Discussion: At the University of Florida, the policy is to treat almost all patients with squamous cell carcinomas of the oropharynx with RT alone or followed by planned neck dissection for patients with clinically involved cervical lymph nodes, reserving surgery for salvage treatment of patients with persistent or recurrent disease after initial treatment
External beam RT for carcinomas of the soft palate is often delivered with megavoltage equipment using parallel-opposed lateral portals treating the soft palate and upper cervical lymph nodes and en face anterior portals treating lower cervical and supraclavicular lymph nodes, shielding the hypopharynx, larynx, and spinal cord. For limited carcinomas of the soft palate, external beam RT delivered with orthovoltage equipment or electrons from megavoltage equipment using intraoral cones may precede external beam RT delivered with megavoltage equipment Limited carcinomas of the soft palate may also be treated with external beam RT followed by interstitial brachytherapy using the guide gutter technique or the plastic tube technique Intraoral cones and interstitial brachytherapy enable delivery of RT to the soft palate while sparing the mandible and salivary glands. For limited carcinomas of the soft palate, RT is associated with relatively high local-regional control and survival rates and satisfactory functional outcome. Local control rates range from 83% to 96% for T1 carcinomas and from 67% to 81% for T2 carcinomas for external beam RT alone and from 85% to 95% for T1 and T2 carcinomas for external beam RT followed by interstitial brachytherapy. Cause-specific survival rates at 5 years for T1 and T2 carcinomas range from 67% to 84% for external beam RT alone and from 64% to 71% for external beam RT followed by interstitial brachytherapy In the present study, local control rates (86% and 91%, respectively) and cause-specific survival rates (75% and 83%, respectively) at 5 years for T1 and T2 carcinomas are similar to those reported by other institutions, if not somewhat better.

For advanced squamous cell carcinomas of the oropharynx, local-regional control and survival rates are relatively low, and local-regional recurrence rates are substantial after RT alone for advanced carcinomas of the soft palate. Local control rates range from 55% to 63% for T3 carcinomas and from 24% to 37% for T4 carcinomas. Cause-specific survival rates at 5 years for T3 and T4 carcinomas range from 25% to 40% for RT In the present study, local control rates (67% and 36%, respectively) and cause-specific survival rates (60% and 25%, respectively) at 5 years for T3 and T4 carcinomas are somewhat better than those reported by other institutions. For advanced carcinomas of the oropharynx, altered fractionation schemes and chemotherapy in combination with RT are promising approaches in attempt to improve local-regional control and survival rates. Improved local-regional control and survival rates are reported for accelerated fractionation schemes and hyperfractionation schemes compared with conventional fractionation schemes. Induction chemotherapy followed by RT is not correlated with improved local-regional control and survival rates when compared to RT aloneRT and concomitant chemotherapy, on the contrary, are associated with improved local-regional control and survival rates when compared with RT alone.

Because the risk of subclinical disease in the clinically negative neck is relatively high, even for early-stage primary cancers, elective neck RT is indicated in all patients Patients with relatively low-volume positive neck nodes that regress completely after RT are observed. Patients with high-volume N2 and N3 neck disease usually undergo a planned neck dissection after RT. Although recent data suggest that the risk of isolated recurrences in the neck is relatively low for patients with N2–N3 neck disease who have a complete response to RT, our policy has generally been to add the neck dissection, because of the low probability of successful salvage and the improvement in cause-specific survival observed in the subset of patients who undergo the operation.

External beam radiation therapy for squamous cell carcinoma of the soft palate.

Medini E, Medini A, Int J Radiat Oncol Biol Phys 1997 Jun 1;38(3):507-11

Department of Radiation Oncology and Otolaryngology, University of Minnesota, and Veterans Administration Medical Center, Minneapolis 55417, USA.

A total of 24 patients with squamous cell carcinoma of the soft palate were treated at the Veterans Administration Medical Center Minneapolis, MN, between February 1977 and May 1992. Of the 24 patients 2 had T1, 19 T2, 1 T3, and 2 had T4 lesions. Nineteen patients did not have clinical nodal disease, stage (N0), 1 had N1, 2 N2, and 2 N3 disease (Table 1). All the patients were treated by 4 MeV linear accelerator. A 1.75 Gy median dose was administered per fraction to a total of 70 Gy median dose. Bilateral opposed compensated shrinking fields technique was used. RESULTS: The 3-year disease free survival rate after external beam radiation therapy was 100% (1 out of 1), 64.7% (11 out of 17), 100% (1 out of 1), and 0%, for patients with T1, T2, T3, and T4 disease, respectively. Salvage surgery for recurrent disease was successful in 57.1% (4 out of 7 patients (Table 2). The ultimate 3-year disease free survival rate for the entire group, including surgical salvage, was 81% (17 out of 21) (Fig 1). CONCLUSION: Radiation therapy alone in our institution resulted in tumor control and survival rates compare favorably to previously published reports in the literature. Surgery can be reserved as salvage procedure.

Results of irradiation in squamous cell carcinoma of the soft palate and uvula.

Keus RB, Pontvert D, Brunin F, Jaulerry C, Bataini JP Radiother Oncol 1988 Apr;11(4):311-7

Radiotherapy Department, The Netherlands Cancer Institute (Antoni van Leeuwenhoekhuis), Amsterdam.

Out of a series of 235 patients presenting with tumours of the soft palate at the Institut Curie, between 1958 and 1980, 146 cases were analysed to evaluate the results of radical radiation therapy. Seventy patients (48%) had advanced T3-T4 disease and 40 patients (27%) had clinically involved metastatic nodes. All patients had a minimum follow-up of 5 years. In 103 cases, megavoltage X-ray therapy was employed. For 43 patients, presenting with small or moderately advanced tumours, a combination of megavoltage and intra-oral orthovoltage X-rays was used. The local control rate at 3 years was 92% for T1, 70% for T2, 58% for T3 and 49% for T4 lesions. Nodal failure was seen in 19 patients. In 9 of these, it was not associated with failure at the primary site, 7 out of 9 occurring marginally or outside the treatment portals. Complications were observed in 16 patients, 7 requiring surgery. The crude 3 and 5 year survival rate was 52 and 40%, respectively, and the disease-free survival 59 and 53%.

Primary radiation therapy in the treatment of squamous cell carcinoma of the soft palate.

Horton D, Tran L, Greenberg P, Selch MT, Parker RG. Cancer 1989 Jun 15;63(12):2442-5

Department of Radiation Oncology, School of Medicine, University of California Los Angeles.

From 1970 to 1986, 45 patients received primary radiation therapy for squamous cell carcinoma of the soft palate at the University of California Los Angeles (UCLA) Center for the Health Sciences and Wadsworth Veteran's Administration Hospital. Seven patients were lost to follow-up or had prior irradiation, and were excluded. Thirty-eight patients received a median dose of 70 Gy (62.5 to 80 Gy) to the primary site. After a median follow-up of 48 months, initial control of disease at the primary site was accomplished in 74% of the patients. The initial control by stage was as follows: TI, 83%, T2, 67%; and T3, 63%. After surgical salvage, local control increased to 92%, 80% and 75% for stages T1, T2, and T3, respectively. Twenty-nine percent (11 of 38) of the patients had cervical node metastases at presentation. Radiation provided regional control in 96% (26 of 27) with N0 disease and 86% (six of seven) with N1 disease at diagnosis. Sixteen patients (42%) had an additional malignancy of the upper aerodigestive tract. Because the incidence of second malignancies after treatment is high and surgical salvage of treatment failures is possible, close follow-up is essential in the management of this tumor. We conclude that radiation therapy is an effective modality for the treatment of squamous cell carcinoma of the soft palate. Primary radiation therapy may offer many patients the chance to avoid surgical procedures that are both cosmetically and functionally debilitating without compromosing treatment outcome.

Carcinoma of the soft palate treated with irradiation: analysis of results and complications.

Amdur RJ, Mendenhall WM, Parsons JT, Isaacs JH Jr, Million RR, Cassisi NJ. Radiother Oncol 1987 Jul;9(3):185-94

This is an analysis of 75 patients with squamous cell carcinoma of the soft palate and/or uvula treated with radical radiation therapy alone (64) or in conjunction with planned neck dissection (11) between October 1964 and September 1983. All patients have a minimum follow-up of 2 years and 60 (80%) have a minimum follow-up of 5 years. Patients were excluded from analysis of disease control at the primary site and/or neck if they died within 2 years of treatment with the site(s) continuously disease free. The initial local control rates and ultimate local control rates after surgical salvage of irradiation failures for patients treated with continuous-course irradiation were as follows: T1, 8/8 (100%) and 8/8 (100%); T2, 14/19 (74%) and 16/19 (84%); T3, 5/11 (45%) and 5/11 (45%); and T4, 1/4 (25%) and 1/4 (25%). Overall, 7/55 patients (13%) treated with continuous-course irradiation experienced irradiation-related bone or soft tissue complications; there was only one severe complication. The 5-year determinate survival rates by modified AJCC stage for patients treated with continuous-course irradiation are as follows: I, 83%; II, 78%; III, 38%; IVA, 0/2; and IVB, 25%

Primary radiation therapy in the treatment of squamous cell carcinoma of the soft palate

David Horton, MD

¹Department of Radiation Oncology, School of Medicine, University of California Los Angeles, Los Angeles, California and the Jonsson Comprehensive Cancer Center
²Wadsworth Veteran' Administration Medical Center, Department of Radiation Oncology, West Los Angeles, California

Cancer 1989;63:2442

From 1970 to 1986, 45 patients received primary radiation therapy for squamous cell carcinoma of the soft palate at the University of California Los Angeles (UCLA) Center for the Health Sciences and Wadsworth Veteran' Administration Hospital. Seven patients were lost to follow-up or had prior irradiation, and were excluded. Thirty-eight patients received a median dose of 70 Gy (62.5 to 80 Gy) to the primary site. After a median follow-up of 48 months, initial control of disease at the primary site was accomplished in 74% of the patients.
The initial control by stage was as follows: T1, 83%; T2, 67%; and T3, 63%. After surgical salvage, local control increased to 92%, 80%, and 75% for stages T1, T2, and T3, respectively. Twenty-nine percent (11 of 38) of the patients had cervical node metastases at presentation. Radiation provided regional control in 96% (26 of 27) with NO disease and 86% (six of seven) with N1 disease at diagnosis. Sixteen patients (42%) had an additional malignancy of the upper aerodigestive tract. Because the incidence of second malignancies after treatment is high and surgical salvage of treatment failures is possible, close follow-up is essential in the management of this tumor. We conclude that radiation therapy is an effective modality for the treatment of squamous cell carcinoma of the soft palate. Primary radiation therapy may offer many patients the chance to avoid surgical procedures that are both cosmetically and functionally debilitating without compromising treatment outcome.