Management of suboptimal response to induction chemotherapy in locoregionally advanced nasopharyngeal carcinoma: Re-induction therapy or direct to Radiotherapy?

Effect analysis of 847 nasopharyngeal carcinoma cases treated with intensity modulated radiation: Experience and suggestions

OBJECTIVES

To identify the failure patterns and prognostic factors of nonmetastatic nasopharyngeal carcinoma (NPC) in the intensity-modulated radiotherapy (IMRT) era.

METHODS

Data on 847 patients with newly diagnosed, non-disseminated NPC treated by IMRT between 2012 and 2016 were retrospectively reviewed. Survival outcome, failure patterns and prognosis factors were analyzed.

RESULTS

The 5-year local relapse-free survival, nodal relapse-free survival, distant metastasis-free survival, disease-free survival, and overall survival rates were 94.3%, 95.3%, 84.8%, 76.5% and 85.7%, respectively. The major local recurrence sites were the nasopharynx (91.5%, 43/47) and skull base (68.1%, 32/47); 39 patients had in-field failures, four had marginal failures, and four had out-field failures. Level IIb (62.2%, 23/37) was the most frequent regional recurrence site, followed by IIa (35.1%, 13/37) and retropharyngeal region (32.4%, 12/37); 35 cases had in-field failure alone, one had out-field failure alone, and one had both in- and out-field failure. TNM stage was the most significant factor for prognosis prediction. 402 (47.5%) patients had acute adverse events of grade 3 or 4; leukopenia (31.5%) and mucositis (26.7%) was the most common hematological and non-hematological event, respectively. Late complications were slight or moderate damages; xerostomia (647/847, 76.4%) and hearing impairment (422/847, 49.8%) remained the most troublesome.

CONCLUSION

NPC patients treated with IMRT obtained satisfactory survival outcomes. The key failure pattern was distant metastasis. The main pattern of local-regional failure was in-field failure. Screening high risk patients with distant metastases and optimizing radiotherapy targets should be studied.

Incorporation of PD-1 blockade into induction chemotherapy improved tumor response in patients with locoregionally advanced nasopharyngeal carcinoma in a retrospective patient cohort

OBJECTIVE

To investigate the short-term efficacy and safety of induction chemotherapy (IC) combined with anti-PD-1 immunotherapy in locoregionally advanced nasopharyngeal carcinoma (LA-NPC).

METHODS

A total of 217 patients diagnosed with LA-NPC at the First Affiliated Hospital of Nanchang University, including 67 who received IC combined with anti-PD-1 and 150 who received IC, were retrospectively enrolled. Efficacy was evaluated at the end of the IC cycles and one month after radiotherapy based on RECIST v1.1 criteria. Acute toxicities were graded based on the CTCAE v5.0 criteria. Quantitative variables were compared by unpaired t-tests, and categorical variables were evaluated by Fisher Freeman-Halton test or Pearson Chi-square test.

RESULTS

At the end of all induction therapy cycles, the objective response rate (ORR) of the IC + anti-PD-1 group was 88.1 % (59/67) as opposed to 70.0 % (105/150) in the IC group. Subgroup analysis showed that patients in both stage Ⅲ and ⅣA achieved a significant improvement in ORR with the inclusion of anti-PD-1 therapy. Patients with T3-4 or N2-3 category appeared to benefit more from anti-PD-1 compared to patients with T1-2 or N0-1 category. However, neither ORR nor the complete response (CR) rate was significantly different between the two treatment groups one month after the end of radiotherapy. In addition, the frequency of Grade 3-4 adverse events were also similar in both groups.

CONCLUSIONS

IC combined with anti-PD-1 immunotherapy significantly improved the ORR of LA-NPC patients after induction therapy compared to IC alone.

Enhancing efficacy and reducing toxicity: Therapeutic optimization in locoregionally advanced nasopharyngeal carcinoma

When applied as the standard therapeutic modality, intensity-modulated radiotherapy (IMRT) improves local control and survival rates in patients with nasopharyngeal carcinoma (NPC). However, distant metastasis continues to be the leading cause of treatment failure. Here, we review the most recent optimization strategies for combining chemotherapy with IMRT in high-risk patients with locoregionally advanced NPC. We focus on major clinical trials on induction chemotherapy and metronomic adjuvant chemotherapy, emphasizing their efficacy in mitigating distant metastasis and prognosis. We also highlight innovations in reducing toxicity in low-risk patients, particularly through approaches of excluding chemotherapy, adopting equivalent low-toxicity drugs, or selectively exempting lymph nodes with low metastatic risk from irradiation. These approaches have provided positive treatment outcomes and significantly enhanced patients' quality of life. Finally, we provide an overview of the evolving immunotherapy landscape, with a focus on the ongoing trials and future potential of immune checkpoint inhibitors in advanced NPC treatment.

Effect of waiting time for radiotherapy after last induction chemotherapy on prognosis of locally advanced nasopharyngeal carcinoma

BACKGROUND

The effect of radiotherapy waiting time after last induction chemotherapy (IC-RT) on prognosis of patients with locally advanced nasopharyngeal carcinoma (LANPC) needs further discussion.

METHODS

Three hundred and six patients with LANPC diagnosed pathologically by induction chemotherapy (IC) and radiotherapy (RT) from 2013 to 2018 were selected for this study.

RESULTS

The IC-RT was a risk factor for the post-treatment progression of LANPC (OR = 1.017 95%CI: 1.003-1.031), For patients with LANPC, the IC-RT > 40 days significantly reduced 5-year PFS (70% vs. 55%; p = 0.0012), 5-year OS (84% vs. 73%; p = 0.028), 5-year DMFS (80% vs. 66%; p = 0.003), 5-year LRFS (77% vs. 67%; p = 0.012). Indicating that patients with stage IVa who IC-RT > 40 days were found to be a significant predictor of aggravated PFS (HR = 2.69; 95%CI: 1.57-4.6), OS (HR = 2.55; 95%CI: 1.29-5.03), DMFS (HR = 3.07; 95%CI: 1.64-5.76) and LRFS (HR = 2.26; 95%CI: 1.21-4.21).

CONCLUSION

The prognosis of patients will be adversely affected if the IC-RT exceeds 40 days, especially for stage IVa patients.

Individualized number of induction chemotherapy cycles for locoregionally advanced nasopharyngeal carcinoma patients based on early tumor response

BACKGROUND

The optimal number of cycles of induction chemotherapy (IC) in locoregionally advanced nasopharyngeal carcinoma (LANPC) is unclear. We aimed to combine the tumor response during IC and tumor stage to individualize the number of IC cycles.

METHODS

Totally, 498 LANPC patients who received IC plus CCRT between 2014 and 2018 were reviewed. Tumor response during IC was used to stratify patients with different risks. All patients were classified into those who received two cycles of IC and those who were treated with three cycles. Propensity score matching methods were performed to compare the treatment efficiency.

RESULTS

After two cycles of IC, 340/498 (68.3%) cases showed complete tumor response (CR)/partial response (PR) and 158 (31.7%) achieved stable disease (SD)/disease progression (PD). Unfavorable responders (SD/PD) exhibited poor survival outcomes. The three-cycle IC regimen was correlated with better OS and PFS than the two-cycle regimen for N2-3 patients in the CR/PR group. However, the use of different IC cycle strategies achieved similar survival outcomes for SD/PD or N0-1 patients. The incidences of acute toxicities were higher in the IC = 3 group.

CONCLUSIONS

Tumor response during IC could be a powerful predictor of LANPC and could be used to guide the individualized number of IC cycles. A three-cycle IC regimen seemed to be preferable for N2-3 patients who received CR/PR during IC. However, an additional cycle of IC could not benefit N0-1 or SD/PD patients, and the optimal treatment strategies for these patients require further consideration.