Chemotherapy May Not be Necessary in Stage II Nasopharyngeal Carcinoma Treated with Intensity-Modulated Radiation Therapy

T1-2N1M0 nasopharyngeal carcinoma chemotherapy or not: A retrospective study

BACKGROUND

Radiotherapy (RT) combined with chemotherapy is the standard treatment for T1-2N1M0 nasopharyngeal carcinoma (NPC) based on conventional radiotherapy. However, intensity-modulated radiotherapy (IMRT) has narrowed the treatment gap between RT and chemoradiotherapy. Thus, this retrospective study aimed to compare the efficacy of RT and chemoradiotherapy (RT-chemo) in treating T1-2N1M0 NPC in the IMRT era.

MATERIALS AND METHODS

From January 2008 to December 2016, 343 consecutive patients with T1-2N1M0 NPC in two cancer centers were included. All patients received RT or RT-chemo, chemotherapy including induction chemotherapy (IC) + concurrent chemoradiotherapy (CCRT), CCRT, or CCRT + adjuvant chemotherapy (AC). The number of patients who received RT, CCRT, IC + CCRT, and CCRT + AC was 114, 101, 89, and 39. The survival rates were analyzed using the Kaplan-Meier method and compared using the log-rank test. Multivariable analysis was performed to identify valuable prognostic factors.

RESULTS

The median follow-up time for survivors was 93 (range: 55-144) months. The 5-year overall survival (OS), progression-free survival (PFS), locoregional failure-free survival (LRFFS), and distant metastasis-free survival (DMFS) for the RT-chemo and RT groups were 93.7%, 88.5%, 93.8%, 93.8% and 93.0%, 87.7%, 91.9%, 91.2%, respectively (P>0.05 for all outcomes). No significant survival differences were found between the two groups. The T1N1M0 or T2N1M0 subgroup analysis showed that treatment outcomes had no significant differences between the RT and RT-chemo groups. After adjusting for various factors, treatment mode was not identified as an independent prognostic factor for all survival rates.

CONCLUSIONS

In this study, outcomes of T1-2N1M0 NPC patients treated by IMRT alone were comparable to chemoradiotherapy, supporting the omission or postponement of chemotherapy.

Explore the Usefulness of Concurrent Chemotherapy in Stage II Nasopharyngeal Carcinoma: A Retrospective Study

Objective: This study aims to compare the treatment outcomes of concurrent chemoradiotherapy (CCRT) versus radiotherapy (RT) alone in stage II nasopharyngeal carcinoma (NPC) patients. Methods: We retrospectively collected 601 stage II NPC patients treated in two hospitals between June 2003 to June 2016. All patients were divided into the CCRT group (n = 255) and the RT group (n = 346). Overall survival (OS), locoregional failure-free survival (LRFFS), progression-free survival (PFS), and distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method. The log-rank test was used to compare the differences between the groups. The Cox-regression hazards model was performed to determine potential prognostic factors. Results: The median follow-up was 99 months. No significant difference was found in locoregional recurrence, distant metastasis, disease progression, and death between the two groups (all p > 0.05). In univariate analysis, the 5-years OS, PFS, LRFFS, and DMFS had no significant differences between the CCRT and RT groups (all p > 0.05). Two-dimensional radiotherapy (2DRT) sub-analysis showed that CCRT remarkably increased DMFS, PFS, and OS rates (all p < 0.05) but not LRFFS (p = 0.258) compared with RT alone. While intensity-modulated radiotherapy (IMRT) sub-analysis showed that the prognosis of the two groups had no significant differences (all p > 0.05). In multivariate analyses, age was significantly and inversely related to OS, PFS, LRFFS, and DMFS. IMRT was an independent favorable factor for improving LRFFS, PFS, and OS. Concurrent chemotherapy was an independent protective factor for DMFS. Conclusion: In the context of 2DRT, it is definite that concurrent chemotherapy provides survival benefits for patients with stage II NPC. While in the IMRT era, the impact of chemotherapy on survival in patients with stage II NPC is weakened. Prospective randomized controlled studies are required to confirm these results.

Adding Concurrent Chemotherapy to Intensity-Modulated Radiotherapy Does Not Improve Treatment Outcomes for Stage II Nasopharyngeal Carcinoma: A Phase 2 Multicenter Clinical Trial

Purpose: To explore the efficacy of concomitant chemotherapy in intensity-modulated radiotherapy (IMRT) to treat stage II nasopharyngeal carcinoma (NPC). Methods and Materials: In this randomized phase 2 study [registered with ClinicalTrials.gov (NCT01187238)], eligible patients with stage II (2010 UICC/AJCC) NPC were randomly assigned to either IMRT alone (RT group) or IMRT combined with concurrent cisplatin (40 mg/m², weekly) (CCRT group). The primary endpoint was overall survival (OS). The second endpoints included local failure-free survival (LFFS), regional failure-free survival (RFFS), disease-free survival (DFS), distant metastasis-free survival (DMFS), and acute toxicities. Results: Between May 2010 to July 2012, 84 patients who met the criteria were randomized to the RT group (n = 43) or the CCRT group (n = 41). The median follow-up time was 75 months. The OS, LFFS, RFFS, DFS, and DMFS for the RT group and CCRT group were 100% vs. 94.0% (p = 0.25), 93.0% vs. 89.3% (p = 0.79), 97.7% vs. 95.1% (p = 0.54), 90.4% vs. 86.6% (p = 0.72), and 95.2% vs. 94.5% (p = 0.77), respectively. A total of 14 patients experienced disease failure, 7 patients in each group. The incidence of grade 2 to 4 leukopenia was higher in the CCRT group (p = 0.022). No significant differences in liver, renal, skin, or mucosal toxicity was observed between the two groups. Conclusion: For patients with stage II NPC, concomitant chemotherapy with IMRT did not improve survival or disease control but had a detrimental effect on bone marrow function.

Depicting distant metastatic risk by refined subgroups derived from the 8th edition nasopharyngeal carcinoma TNM

BACKGROUND

Tumor-nodal-metastasis (TNM) is the most important survival predictor in nasopharyngeal carcinoma (NPC). Distant metastasis (DM) is the predominant failure pattern of NPC in the intensity-modulated radiotherapy (IMRT) era. The DM risk appears to be different for T-N subsets within the same clinical stage. Appropriately depicting DM risk has emerged as an important issue in tailoring individualized treatment and underpins the reason for this study.

METHODS

A total of 1616 non-metastatic (M0) NPC patients treated with IMRT were included. All were re-staged according to the 8th edition AJCC/UICC TNM (TNM-8). DM-free survival (DMFS) was calculated and compared among T-N subsets within each stage and DM risk groups were derived by Recursive-partitioning analysis (RPA) based on ordinal T and N categories.

RESULTS

Significant heterogeneity in DM risk was evident among T-N subsets within cTNM-8 stages II-IV. The RPA algorithm classified patients into four DM risk groups: RPA-I (T1N0-1 and T2-3N0), RPA-II (T2-3N1), RPA-III (T4N0-1 and T1-3N2) and RPA-IV (T4N2 and T1-4N3), with 5-year DMFS of 93.4% (95% CI: 91.3-96.1), 84.3% (80.8-87.8), 78.9% (75.4-82.4) and 63.6% (56.3-70.9), respectively (p < 0.001). Compared to cTNM-8 stage grouping, RPA grouping had a lower Akaike information criterion (AIC) and higher Harrell's concordance index (c-index) for DMFS.

CONCLUSIONS

Significant heterogeneity in DM risk exists among T-N subsets within cTNM-8 stages. The RPA groups demonstrated improved intra-group hazard consistency compared to cTNM-8 stage groups. While further validation is warranted, these RPA prognostic groupings provide a strong anatomic foundation to augment DM prediction for optimal targeting in future clinical trials.