Long-term treatment results for nasopharyngeal carcinoma: the Sahlgrenska University Hospital experience

Long-Term Outcomes of Nasopharyngeal Carcinoma in 148 Children and Adolescents

The aim of this study was to investigate the survival and long-term morbidities of nasopharyngeal carcinoma (NPC) in children and adolescents.We retrospectively reviewed children and adolescents with NPC treated at Sun Yat-sen University Cancer Center from February 1991 to October 2010, where the prognostic factors and long-term effects of therapy were analyzed.A total of 148 patients were identified. The median age was 15 years old (range, 5-18 years) and the male to female ratio was 3.6:1. Most of the tumor histopathology was undifferentiated nonkeratinizing carcinoma (97.3%). The number of patients staged with IVa, IVb, IVc, III, and II were 45 (30.4%), 12 (8.1%), 5 (3.4%), 70 (47.3%), and 16 (10.8%), respectively. For the whole series with a median follow-up of 81 months (range, 6-282 months), the 5-year overall survival (OS) and disease-free survival (DFS) ratios were 79.3% and 69.7%, respectively. We observed significant differences in the 5-year OS (81.1% vs 25.0%, P = 0.002) and the DFS rates (72.2% vs 0.0%, P = 0.000) between patients with stage II to IVb disease and stage IVc disease. For patients with stage II, III, IVa, and IVb disease, we found a high radiation dose (dose > 66 Gy to the primary lesion) would not significantly improve the survival compared to the sub-high radiation dose group (dose = 60-66 Gy to the primary lesion), even considering the type of radiation therapy technologies. However, the incidences of sequelae (grades I-IV) in patients with high radiation dose were apparently higher than those in patients with low radiation dose.Considering the late sequelae, a dose of 60 to 66 Gy to the primary lesions seems to be enough for children and adolescents with NPC.

Different therapeutic strategies in primary salivary gland-type nasopharyngeal carcinomas

PURPOSE OF REVIEW

Primary salivary gland-type nasopharyngeal carcinoma (PSGT-NPC) is an uncommon malignancy with aggressive behavior and poor prognosis. Its optimal treatment policy remains debated, even though recent evidence provides support for a multimodality approach. The aim of this study was to summarize the optimal management approaches and treatment outcomes of PSGT-NPCs.

RECENT FINDINGS

As most of the PSGT-NPCs, such as adenoid cystic carcinoma, mucoepidermoid carcinoma and low-grade (well-differentiated) adenocarcinoma, have low sensitivity to radiation, combined surgical treatment and radiotherapy are still the main treatment approach for limited or resectable lesions. As a result of the fact that in well-differentiated PSGT-NPCs the occult neck metastasis rate is low (less than 20%), elective neck dissection is not recommended in patients with a node-negative neck. Since high-grade (poorly-differentiated) PSGT-NPCs are relatively sensitive to radiation, radiotherapy or chemoradiotherapy is currently considered as the main treatment policy for such patients. There is no evidence to indicate that chemotherapy would improve overall survival. Cranial nerve infiltration, residual tumor, and distant metastases are independent predictive factors of overall survival.

SUMMARY

In most patients with PSGT-NPCs, especially for well-differentiated tumors, combined surgical treatment and radiotherapy should be recommended. For poorly-differentiated or unresectable tumors, radiotherapy or chemoradiotherapy is still considered the main treatment approach. Because of the rare incidence of PSGT-NPCs, the number of cases available for analysis is relatively small, and large multicentric studies should be conducted to further evaluate their optimal treatment policy.

Primary salivary gland type carcinoma of the nasopharynx: therapeutic outcomes and prognostic factors

BACKGROUND

Primary salivary gland type nasopharyngeal carcinoma (SNPC) is a rare malignancy with diverse clinical behavior and different prognoses. Previous studies have reported on limited patient populations, and few long-term studies have outlined outcomes and prognostic factors. Furthermore, controversy exists as to the treatment policy of SNPC. The aim of this study was to define management approaches, therapeutic outcomes, and prognostic factors of SNPC.

METHODS

The medical records of 67 patients with SNPC at 1 institution between 1977 and 2005 were reviewed. Patient records were analyzed for management approaches, outcomes, and prognostic factors.

RESULTS

SNPC is a rare malignancy accounting for only 0.29% of nasopharyngeal malignancies, and the lymphatic metastases and distant metastases rates were 28.4% and 23.9%, respectively. The 5-year disease-free survival (DFS) and overall survival (OS) rates were 41.1% and 57.1%, respectively; no significant differences were found in DFS or OS between different histological subtypes. A significant difference was found in OS between surgical treatment and nonsurgical treatment in T1-T2 patients with well-differentiated tumors. Multivariate analyses indicated that lymph node metastases, stage, and distant metastases were independent factors for DFS, whereas cranial nerve invasion, tumor residue, and distant metastases were independent factors affecting OS.

CONCLUSIONS

SNPC is a malignancy with generally favorable prognosis. In T1-T2 patients with well-differentiated tumors, SNPC should be treated by combined surgical operation and radiotherapy. Cranial nerve invasion, tumor residue, and distant metastases were independent factors affecting OS.

Intensity-modulated radiotherapy of nasopharyngeal carcinoma: a comparative treatment planning study of photons and protons

BACKGROUND

The aim of this treatment planning study was to investigate the potential advantages of intensity-modulated (IM) proton therapy (IMPT) compared with IM photon therapy (IMRT) in nasopharyngeal carcinoma (NPC).

METHODS

Eight NPC patients were chosen. The dose prescriptions in cobalt Gray equivalent (GyE) for gross tumor volumes of the primary tumor (GTV-T), planning target volumes of GTV-T and metastatic (PTV-TN) and elective (PTV-N) lymph node stations were 72.6 GyE, 66 GyE, and 52.8 GyE, respectively. For each patient, nine coplanar fields IMRT with step-and-shoot technique and 3D spot-scanned three coplanar fields IMPT plans were prepared. Both modalities were planned in 33 fractions to be delivered with a simultaneous integrated boost technique. All plans were prepared and optimized by using the research version of the inverse treatment planning system KonRad (DKFZ, Heidelberg).

RESULTS

Both treatment techniques were equal in terms of averaged mean dose to target volumes. IMPT plans significantly improved the tumor coverage and conformation (P < 0.05) and they reduced the averaged mean dose to several organs at risk (OARs) by a factor of 2-3. The low-to-medium dose volumes (0.33-13.2 GyE) were more than doubled by IMRT plans.

CONCLUSION

In radiotherapy of NPC patients, three-field IMPT has greater potential than nine-field IMRT with respect to tumor coverage and reduction of the integral dose to OARs and non-specific normal tissues. The practicality of IMPT in NPC deserves further exploration when this technique becomes available on wider clinical scale.