Lung cancer resection rates have increased significantly in females during a 15-year period☆

Abstract

The aim was to carry out a comparative study of lung cancer incidence and resection rates following the introduction of positron emission tomography-computed tomography (PET-CT) and the reorganisation of Cancer Services in Northern Ireland. Data were retrieved from the Regional Thoracic Service Database and Northern Ireland Cancer Registry (NICR) covering the period 1994-2008. The two databases are maintained independently. A total of 13288 lung cancer cases and 1575 lung resections were identified. Secondary tumours were excluded. The incidence of lung tumours and procedures performed was available for each individual year. The incidence of lung cancer was taken from the NICR. The NICR confirmed the diagnosis of lung cancer using international guidelines and cancer was confirmed by histology, cytology, radiological investigations and post-mortem examinations. Poisson regression was used to model the incidence and resections per year; logistic regression was used to model the yearly rate of resections per incidence case. The 15-year period was divided into three periods to assess trends in surgical resection, but the surgical resection rate (SRR) was calculated on a yearly basis. The regional incidence of lung cancer in Northern Ireland (NI) females has increased (1.7% per annum P<0.01, Poisson regression), but this increase has not been seen in males. The incidence of lung cancer patients, who underwent resection at the regional Thoracic Surgery Unit, increased for females (4.4% per annum, P<0.01, Poisson regression), but not for males. The proportional rate of resection (number of resections in a given year/incidence in that year) has changed significantly over the study period for females but not males (the odds ratio per unit year was 1.029, P<0.01, logistic regression). The average age of females increased by 0.2 year (P<0.01) annually; there was no significant increase in the age of males over this period. There was no significant overall rise in the number of patients diagnosed with non-small-cell lung cancer (NSCLC). The percentage of all lung cancer patients who were discussed at multidisciplinary team (MDT) meetings rose from 19% in 1996 to 64% in 2006. The percentage of patients aged over 75 years discussed at an MDT increased from 12% in 1996 to 58% in 2006. The number of females presenting with NSCLC and the number of people presenting with stage I and II disease did not change over the time frame. More patients aged above 70 years had an operation in group III. These accounted for over 50% of the increase in operations between the first and last group. The number of females in this group rose by 92% compared with group I. Significantly, more patients aged over 80 years had an operation in group III than in group I; however, there was significantly more males treated surgically aged over 80 years than females; P=0.001. The resection rate is currently higher in females than males, and has significantly increased during the study period. The incidence in female lung cancer has risen but it is still below male incidence rates. It seems unlikely that one single factor has brought about this increase. With better education among medical practitioners and the public, more lung cancer cases have been considered for surgery by surgeons. There has been an overall increase in patients presented at MDTs involving thoracic surgeons. For whatever reason, it appears that many lung cancer cases in females had previously not been presented to surgeons prior to the introduction of MDT meetings practice guidelines. The development of MDT meetings throughout NI along with the close involvement of the Thoracic Surgical Unit from the inception of all MDTs seems the most likely factor leading to a change in lung cancer resection rates.