Impact of the addition of chemotherapy to radiotherapy for oropharyngeal cancer in 2003-2004: Population-based study from the Province of Ontario, Canada

The addition of chemotherapy to radiotherapy did not reduce the rate of distant metastases in low-risk HPV-related oropharyngeal cancer in a real-world setting

Background

Distant metastases (DM) are a leading cause of death for patients with oropharyngeal cancer (OPSCC). The objective of this study was to compare the rates of DM after chemoradiotherapy (CRT) and radiotherapy alone (RT) in patients with human papillomavirus (HPV)‐positive and HPV‐negative OPSCC.

Method

In a retrospective population‐based study of 525 patients across Ontario, Canada, in 1998/99/03/04, we compared treatment effectiveness using cumulative incidence function curves and cause‐specific Cox regression models.

Results

Sixty of 525 patients developed DM. There was no difference in rates (overall 10%‐15%) between HPV‐positive and HPV‐negative patients or between CRT‐ and RT‐treated patients. CRT reduced the risk of DM for the 15% of all HPV‐positive patients with higher risk (T4 and/or N3) and not for HPV‐negative patients (hazard ratio, 1.82 [0.65‐5.07]).

Conclusion

The addition of platin‐based chemotherapy to conventional RT did not decrease the rates of DM in the majority of patients with HPV‐positive or in HPV‐negative OPSSC.

Did the addition of concurrent chemotherapy to conventional radiotherapy improve survival for patients with HPV+ve and HPV-ve Oropharynx cancer? A population-based study

BACKGROUND

In the absence of clear evidence on the efficacy of concurrent chemoradiotherapy (CRT) over conventional radiotherapy (RT) for HPV+ve and for HPV-ve oropharyngeal cancer (OPC), this study compares the treatments and outcomes from pre-CRT years to post-CRT years.

METHODS

A population-based retrospective treatment-effectiveness study based on all patients with OPC treated in Ontario Canada in 1998, 1999, 2003 and 2004. Charts were reviewed, tissue samples were requested and tissue was tested for p16 or in situ hybridisation. Overall survival (OS) and disease-specific survival (DSS) were compared by treatment era and by treatment type for all 1028 patients, for 865 treated for cure and for 610 with HPV status.

RESULTS

There was no improvement in OS comparing pre-CRT to post-CRT eras for the HPV+ve patients (P=0.147) or for the HPV-ve patients (P=0.362). There was no difference in OS comparing CRT to RT for the HPV+ve cohort (HR=0.948 (0.642-1.400)) or for the HPV-ve patients (HR=1.083 (0.68-1.727)).

CONCLUSIONS

In these 'real-world' patients what appeared to be improvements in OS with CRT in clinical trials were confounded by HPV status in Ontario. CRT did not improve outcomes for HPV+ve or for HPV-ve patients.

Do Lower-Risk Thyroid Cancer Patients Who Live in Regions with More Aggressive Treatments Have Better Outcomes?

BACKGROUND

The management of differentiated thyroid cancer has traditionally consisted of total thyroidectomy with or without adjuvant radioactive iodine. However, in the last two decades, this approach has been challenged, with the consideration of more conservative approaches such as less radical surgery and deferring adjuvant treatment, especially in lower-risk patients. The objective of this study was to consider the effectiveness of current treatment options by comparing the survival outcomes from different geographic regions with different treatment philosophies. This study design was based on the concept of natural experiments in patient care that occur when physicians in different regions treat the spectrum of typical patients with varying treatments.

METHOD

This population-based retrospective cohort study investigated 2444 patients with differentiated thyroid cancer ≤4 cm between 1990 and 2001 from Ontario, Canada. Extent of disease and extent of surgery were abstracted from pathology reports and were linked to downstream administrative medical information on treatments and outcomes. Patient demographics, tumor characteristics, treatments, and outcomes were compared between those geographic regions with more aggressive treatments and those regions with less aggressive treatments.

RESULTS

Treatment varied across the province. When comparing outcomes in regions where patients had more extensive treatment to those in regions where patients had less extensive therapy, similar rates were found for 15-year survival, recurrence, and survival after recurrence.

CONCLUSION

There were significant variations in treatment but no differences in outcomes for regions with more versus less aggressive approaches. These findings support the trend toward more conservative management approaches in the treatment of thyroid cancer.

Adherence to and uptake of clinical practice guidelines: lessons learned from a clinical practice guideline on chemotherapy concomitant with radiotherapy in head-and-neck cancer

BACKGROUND

Clinical practice guidelines (cpgs) are systematically developed statements designed to assist practitioners and patients in making decisions about appropriate heath care interventions. Clinical practice guidelines are expensive and time-consuming to create. A cpg on concurrent chemotherapy with radiation therapy (ccrt) was developed in Ontario at a time when treatment approaches for head-and-neck cancer were changing significantly.

METHODS

An assessment of treatments and outcomes based on electronic and chart data obtained from a population-based study of 571 patients with oropharynx cancer treated in Ontario (2003-2004) was combined with a review of relevant knowledge transfer (publications and presentations at major meetings) to understand variation in adherence to a cpg.

RESULTS

In 9 Ontario cancer treatment centres, ccrt was used for 55% of all patients with oropharyngeal cancer; however, at the centres individually, that proportion ranged from 82% to 39%. Furthermore, there was no agreement on the chemotherapy regimen: 2-4 years later (a period during which newer regimens were emerging), only 4 of 9 centres were following the guideline for most patients. When outcomes of treated patients were compared for centres with "higher" and "lower" use of ccrt, no difference in survival was observed (p = 0.64).

CONCLUSIONS

At a time of treatment evolution, the new guideline was controversial, and there are many reasons for the mixed adherence. An estimation of adherence should be included during both development and review of guidelines.