In 1958, Edward L. Kaplan and Paul Meier collaborated to publish a seminal paper on how to deal with incomplete observations. Subsequently, the Kaplan-Meier curves and estimates of survival data have become a familiar way of dealing with differing survival times (times-to-event), especially when not all the subjects continue in the study. “Survival” times need not relate to actual survival with death being the event; the “event” may be any event of interest. Kaplan-Meier analyses are also used in non-medical disciplines.
The purpose of this paper is to explain how Kaplan-Meier curves are generated and analyzed. Throughout this article we will discuss Kaplan-Meier (K-M) estimates in the context of “survival” before the event of interest. Two small groups of hypothetical data are used as examples in order for the reader to clearly see how the process works. These examples also illustrate the crucially important point that comparative analysis depends upon the whole curve and not upon isolated points.
◥Purpose: Pembrolizumab improved survival in patients with recurrent or metastatic head and neck squamous-cell carcinoma (HNSCC). The aims of this study were to determine if pembrolizumab would be safe, result in pathologic tumor response (pTR), and lower the relapse rate in patients with resectable human papillomavirus (HPV)-unrelated HNSCC.Patients and Methods: Neoadjuvant pembrolizumab (200 mg) was administered and followed 2 to 3 weeks later by surgical tumor ablation. Postoperative (chemo)radiation was planned. Patients with high-risk pathology (positive margins and/or extranodal extension) received adjuvant pembrolizumab. pTR was quantified as the proportion of the resection bed with tumor necrosis, keratinous debris, and giant cells/histiocytes: pTR-0 (<10%), pTR-1 (10%-49%), and pTR-2 (≥50%). Coprimary endpoints were pTR-2 among all patients and 1-year relapse rate in patients with high-risk pathology (historical: 35%). Correlations of baseline PD-L1 and T-cell infiltration with pTR were assessed. Tumor clonal dynamics were evaluated (Clin-icalTrials.gov NCT02296684).Results: Thirty-six patients enrolled. After neoadjuvant pembrolizumab, serious (grades 3-4) adverse events and unexpected surgical delays/complications did not occur. pTR-2 occurred in eight patients (22%), and pTR-1 in eight other patients (22%). One-year relapse rate among 18 patients with high-risk pathology was 16.7% (95% confidence interval, 3.6%-41.4%). pTR ≥10% correlated with baseline tumor PD-L1, immune infiltrate, and IFNg activity. Matched samples showed upregulation of inhibitory checkpoints in patients with pTR-0 and confirmed clonal loss in some patients.Conclusions: Among patients with locally advanced, HPVunrelated HNSCC, pembrolizumab was safe, and any pathologic response was observed in 44% of patients with 0% pathologic complete responses. The 1-year relapse rate in patients with high-risk pathology was lower than historical.
Objectives/Hypothesis
Document survival, prognostic variables, and functional outcomes of patients with AJCC stage III or IV oropharyngeal cancer, treated with transoral laser microsurgery (TLM) ± adjuvant therapy.
Study Design
Analysis of prospectively assembled data pertaining to the above-described patient cohort.
Methods
Patients treated with TLM for AJCC stage III or IV oropharyngeal cancer at Washington University School of Medicine from 1996 to 2006 were followed for a minimum of 2 years. Recurrence, survival, functional, and human papilloma virus data were analyzed.
Results
Eighty-four patients met inclusion criteria. Mean follow-up was 52.6 months. Overall AJCC stages were: III 15% and IV 85%. T stages were T1–2, 74%; T3–4, 26%. Eighty-three patients underwent neck dissection, 50 received adjuvant radiotherapy, and 28 received adjuvant chemoradiotherapy. Overall survival at 2 and 5 years was 94% and 88%, respectively. Disease-specific survival at 2 and 5 years was 96% and 92%, respectively. Six patients recurred (7%): locally (one), regionally (four), and distant (five). T stage, positive margins, and p16 status significantly impacted survival. The addition of adjuvant chemo-therapy in high-risk patients did not significantly impact survival. Five patients (6%) had major surgical complications, but without mortality. Eighty-one percent of patients had acceptable swallowing function at last follow-up. Immediately postoperatively, 17% required G-tubes, which dropped to 3.4% of living patients at 3 years.
Conclusions
In this population, our findings validate TLM ± adjuvant therapy as a highly effective strategy for survival, locoregional control, and swallowing recovery in AJCC stage III and IV oropharyngeal cancer. Our finding also show that p16 positivity improves survival.
TLM management of occult primary malignancies allowed high detection rates of primary tumor and was associated with a high level of DFS. Application of TLM during EUA both detects and treats the primary and may decrease the number of patients requiring wide-field irradiation.
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