Lung cancer in Victoria: are we making progress?

Lung cancer is the greatest single cause of cancer death in Australia for both men and women.1,2 Despite Australia having some of the best outcomes internationally, the 5-year relative survival rate is less than 15%.2,3

Our previously reported survey of cases of lung cancer, reported to the Victorian Cancer Registry in the first half of 1993, identified opportunities to improve patient management.4,5 Since that time, there have been a number of important developments in staging and treatment for this disease.6-8

In this study, 10 years on, we present the results of a detailed survey of Victorian patients who presented with lung cancer in 2003 and who were followed for 5 years to provide updated and additional information, including changes over the decade.

We surveyed all people who were diagnosed with lung cancer from 1 January to 30 June 2003 and identified by the Victorian Cancer Registry; postmortem diagnoses were excluded. Ethics approval was obtained from the Cancer Council Victoria Institutional Ethics Committee. A questionnaire relating to management was sent to the treating clinicians, and non-responding clinicians were actively followed up to obtain data. Comorbid conditions were scored according to the Colinet simplified comorbidity score.9 Statistical analysis was performed using SPSS, version 14.0, release 14.0.2 (SPSS Inc). Overall survival was estimated using actuarial methods, and 5-year survival proportions with 95% CIs are shown. Multivariate analysis to determine the effect of prognostic and treatment factors on survival was carried out using Cox proportional hazards regression analysis.

Nine hundred and twenty-one eligible cases were reported and 841 (91.3%) were included in the survey. Reasons for cases not being included were: doctor refusing or being unavailable (48); record unavailable (21); and other (11). The characteristics of the 841 patients are shown in Box 1. For 194 patients (23.1%), lung cancer was diagnosed in the absence of symptoms, mostly as a result of imaging performed for other reasons. Only 16 patients (1.9%) were diagnosed by a screening chest x-ray and/or computed tomography scan. Thirty-three patients (3.9%) were recruited to a clinical trial.

In this study we were able to obtain data for over 90% of reported cases which is a high proportion compared with some other studies.10 Although 92.1% of patients had smoked, only a third were current smokers. For smokers with lung cancer, exposure to tobacco, as indicated by pack years, was 29% less for women, which is consistent with the previously reported observation that women are more susceptible to carcinogens in tobacco smoke.11

There was no pathologically confirmed diagnosis for 10.1% of Victorian patients, which was a lower percentage than in New South Wales, Queensland, New Zealand and the United Kingdom.10,12-14 Patients with no pathologically confirmed diagnosis had a median survival time of just over a month, and very few received treatment. It is unclear if any of these patients might have benefited from treatment, and some may have had non-malignant but fatal conditions such as tuberculosis.

Of all Victorian patients with lung cancer, 97.5% (820 of 841) were referred to a specialist before treatment, which is considerably higher than in NSW, Scotland and New Zealand.10,13,15 Although initial referrals to palliative care physicians were infrequent, over 40% of cases later involved palliative care physicians. The proportion of all cases discussed at an MDM was low at 29% (234 of 797 with available data), similar to New Zealand, but has increased to 49% more recently.13,16

Patients whose cases were discussed at an MDM were more likely to be treated and had significantly better survival. Although cases that were discussed had a number of good prognostic features, on multivariate analysis (rerun with MDM added), discussion at an MDM was an independent prognostic factor for survival. Other researchers have identified more frequent active treatment17 as well as improved survival13 associated with discussion at an MDM. However, our data indicating that the survival benefit is maintained in both a landmark and a multivariate analysis provide a strong rationale for all cases to be discussed at an MDM.

The use of PET scan staging in about 43% (283 of 655) of all and 80% (158 of 198 [comprising 97 of 125 surgical patients and 61 of 97 patients treated with radiotherapy]) of curative NSCLC cases was considerably higher than in NSW.10 PET scans are particularly useful in mediastinal staging and identifying unrecognised metastases.6 Despite about 26% of patients with NSCLC having Stage III disease, only around 8% (51 of 655) had invasive staging of the mediastinum, suggesting that some who underwent surgery or radiotherapy were inadequately staged.

Around 30% of patients with NSCLC underwent treatment with curative intent, including 19.1% going to surgery, which is a higher proportion than in NSW, New Zealand and the UK.10,13,14 Adjuvant chemotherapy rates were very low despite trials supporting adjuvant chemotherapy having just been reported at conferences by 2003.18 Overall, around 11% of patients with NSCLC underwent radiotherapy with curative intent, with about 73% (53 of 73 with available data) being given as concurrent chemoradiation, which is the standard of care.8

The use of both chemotherapy19 and radiotherapy20 was low, although higher than in NSW.10 Over 21% of patients diagnosed with NSCLC received no treatment at all, which is of concern, although this rate was lower than that in NSW10 and the UK.14 We have not analysed this group closely but as more effective therapies with low toxicity (eg, epidermal growth factor receptor inhibitors) become available, it is likely that many patients will be suitable for molecular therapies despite not being suitable for chemotherapy.

As expected, around a third of patients with SCLC had limited stage disease, and most were treated with curative intent. These patients generally received chemotherapy along with thoracic radiotherapy, which is standard of care.21

It has been widely reported that outcomes for patients with lung cancer Australia who live outside major metropolitan centres are worse,2 but we did not see any significant difference in this study after adjusting for age and sex. However, on multivariate analysis, survival was significantly worse for two of the regional/rural cancer networks. These data would need to be confirmed by an analysis covering a longer time period, as the annual number of cases was small.

As in many other developed countries, the proportion of women with lung cancer increased over the decade from 1993 to 2003 while the proportion of patients with SCLC continued to decrease and, for patients with NSCLC, adenocarcinoma became more frequent than squamous cell carcinoma. The age of patients diagnosed with lung cancer increased by almost 3 years, considerably more than for other cancers. This may have been due to changing smoking habits, with patients in the more recent cohorts having not smoked as heavily as those in earlier cohorts, while this reduced intensity of tobacco exposure was associated with a later onset of the malignancy.22 The use of PET scanning increased considerably while the proportion of patients with NSCLC undergoing surgery with curative intent dropped by 6.2% (Box 5). It is likely that PET scanning prevented some patients going to surgery by identifying occult mediastinal or metastatic disease, with no detriment to survival. The use of combination chemoradiotherapy was much more frequent in 2003 than a decade earlier, in line with guidelines and best practice.8 On the other hand, pathologically confirmed staging of the mediastinum was infrequent. Since 2003, imaging and biopsy by endobronchial ultrasound has become more widely available, obviating the need for mediastinoscopy for many patients.23

Although we did not identify a change in crude survival over the decade, statewide data for all Victorian patients with lung cancer over 2 decades have identified a steady improvement in 5-year relative survival from 9% in 1991–1995 to 11% in 2001–2005 and 14% for 2006–2010 (and 20% for patients with NSCLC).24 Relative survival refers to the survival detriment compared with the age matched population without lung cancer.

Our approach in this survey, where we analysed a cohort followed for 5 years, means that our findings may not represent current practice. In light of this, a lung cancer registry has recently been established in Victoria, where cases are identified at diagnosis and data are collected prospectively.

Lung cancer survival clearly remains very poor, and although some progress has been made in better staging and greater use of multimodality therapy, our study has identified several areas that require improved patient management. These include increasing the proportions of patients who receive tissue diagnoses, receive active treatment, have PET scans (if curable), and receive postsurgical adjuvant chemotherapy. Of critical importance, our data support all cases of lung cancer being discussed at an MDM, which appears to be associated with a survival advantage. However, it is important to recognise that despite these measures, two-thirds of patients will continue to present with incurable disease. Besides tobacco control, early diagnosis is crucial, and this may be achieved by measures such as screening of smokers by low radiation dose computed tomography scanning.25