Medical Research Unit, The University of Waikato, Hamilton, New Zealand
Waikato District Health Board, Hamilton, New Zealand

Introduction

Lung cancer is the leading cause of cancer death in New Zealand with approximately 1500 deaths per year (1). It has a significant impact due to the high rates of morbidity and mortality associated with the disease.(2) Survival from lung cancer in New Zealand is poor with a five year survival of 9.5% for men and 11% for women (3, 4). Māori have a greater incidence of lung cancer with Māori men having 2.0 times the incidence and Māori women having 3.4 times the incidence of Europeans/others (1, 5). The age standardised mortality rate for Māori is 3.5 times that of non-Māori (6). One of the key reasons for the poor prognosis for newly diagnosed patients with lung cancer is that most patients presented with advanced stage disease. Treatment is therefore generally palliative, with few patients being suitable for potentially curative treatment such as surgery and stereotactic ablative body radiotherapy (SABR).(7, 8) Another important influence in patient outcome is the tumour biology, for instance those with small cell lung cancer have a poorer prognosis or non-small cell lung cancer (NSCLC) who are epidermal growth factor receptor (EGFR) positive.(9, 10)

New Zealand Cancer Registry (NZCR) is a population-based tumour registry excluding non-melanoma skin cancers), collecting and storing cancer incidence data. The new cancer registrations were mainly based on the pathology reports sent by reporting laboratories electronically. Other sources s include discharge reports from publicly funded and private hospitals, death certificates and autopsy reports.(11, 12) Data collected in the NZCR includes demographic information (such as date of birth, gender and ethnicity), and tumour information (such as cancer site and extent of disease). The NZCR is the major source of ‘information on the incidence of, and mortality from, cancer’ and ‘a basis for cancer survival studies and research programmes’.(13) Its completeness and accuracy are vital for cancer control in New Zealand.

The completeness and accuracy of registrations in the NZCR were reported to be diverse for different cancers.(12, 14-16) Approximately 88% of the breast cancer cases recorded in the NZCR have information on disease extent with a 94% accuracy rate in those with disease extent,(12) and 96% cases with disease extent and a 87% accuracy rate for colon cancer,(14) compared to only 31% cases with disease extent and a 89% accuracy rate for prostate cancer.(15) An audit was conducted to assess the lung cancer data in NZCR using the data recorded in the Auckland and Northland regional databases in 2004.(16) Of the 565 audit cases, 66 (12%) cases were not included in the NZCR, and 1 duplicate registration and 78 (14%) 4

ineligible case were identified in the NZCR. Only 58% of the lung cancer cases recorded in the NZCR have information on disease extent with a 79% accuracy rate in those with disease extent.(16) The audit of the lung cancer data in the NZCR was conducted a decade ago, and improvement on data quality may have been achieved. An updated quality assessment on the lung cancer data is needed.

The Midland Respiratory Group have been collecting data on all newly diagnosed cases of lung cancer who are referred to their multidisciplinary review meetings onto an access database: Midland Lung Cancer register (MLCR). It has maintained a register of all patients seen since 2004 and the centre has relatively complete recording of cases for the Midland Cancer Region (Lakes, Waikato and Bay of Plenty District Health Board) since 2007. These three DHBs serve a combined population of 660,000 and generate approximately 300 new cases a year. The region has 27% Māori population and of the over 2000 cases on the register 600 are Māori. The register includes data on date and source of presentation, results of investigations including CT and spirometry, date of diagnosis and pathological reporting. All patients are staged and mode of treatment is then recorded (radiotherapy, chemotherapy or surgery).

This study aims to 1) report the characteristics of newly diagnosed lung cancer cases, 2) compare the data accuracy of registrations in the NZCR with the MLCR, and 3) examine the treatment and survival of these patients.