Are There Differences by sex in Lung Cancer Characteristics at Diagnosis? 

A Nationwide Study

Alberto Ruano-Ravina; Mariano Provencio; Virginia Calvo de Juan; Enric Carcereny; Anna Estival; Delvys Rodríguez-Abreu; Gretel Benítez; Rafael López-Castro; Marta Belver; María Guirado-Risueño; Carlos Guirao-Rubio; Ana Blasco; Bartomeu Massutí; Ana Laura Ortega; Manuel Cobo; Joaquín Mosquera-Martínez; Carlos Aguado de la Rosa; Joaquim Bosch-Barrera; Amparo Sánchez-Gastaldo; Edel del Barco Morillo; Óscar Juan; Manuel Dómine; José Manuel Trigo; Diego Pereiro Corbacho; Juana Oramas


Transl Lung Cancer Res. 2021;10(10):3902-3911. 

In This Article

Abstract and Introduction


Background: Lung cancer causes approximately 25% of all cancer deaths. Despite its relevance, few studies have analyzed differences by sex at the time of diagnosis in terms of symptoms, stage, age or smoking status. We aim to assess if there are differences between men and women on these characteristics at diagnosis.

Methods: We analyzed the Thoracic Tumour Registry (TTR), sponsored by the Spanish Lung Cancer Group using a case-series design. This is a nationwide registry of lung cancer cases which started recruitment in 2016. For each case included, clinicians fulfilled an electronic record registering demographic data, symptoms, exposure to lung cancer risk factors, and treatment received in detail. We compared men and women using descriptive statistics.

Results: A total of 13,590 participants took part in this study, 25.6% women. Women were 4 years younger than men (64 vs. 69), and men had smoked more frequently. Adenocarcinoma was the most frequent histological type in both sexes. Stage IV at diagnosis was 50.8% in women compared to 43.6% in men. Weight loss/anorexia/asthenia was the most frequent symptom in both sexes and there were no differences in the number of symptoms at diagnosis. There were no relevant differences in the frequency or number of symptoms by sex when non-small cell lung cancer (NSCLC) and small-cell lung cancer (SCLC) were analyzed separately. Smoking status did not appear to cause different lung cancer presentation in men compared to women.

Conclusions: There seems to be no differences in lung cancer characteristics by sex at the time at diagnosis on stage, specific symptoms or number of symptoms.


Lung cancer is a relevant health problem. It is estimated that in 2020 it will be the second most incident cancer in US men and women (following prostate and breast cancer, respectively),[1] but it will be the most deadly cancer in both sexes, with a number of deaths very close to the numbers of colon and rectum, pancreas and breast cancers combined. In fact, in Europe and also in Spain, lung cancer is the deadliest cancer.[2] The number of new lung cancer cases in Spain for 2021 has been estimated in 29,000.[3] The estimated 5-survival according to SEER data for the period 2010–2016 is 20.5%.[4] The Concord-3 study estimated this survival for the period 2010–2014 in the range of 10−20% through pooling data from different world cancer registries.[5]

It is unknown if lung cancer risk may differ between men and women, but there are differences regarding the frequency of histological types. Squamous cell carcinoma and small cell carcinoma are more frequent in males while adenocarcinoma is more frequent in females. This difference has been explained by the differences in the consumption of tobacco type between men and women (dark vs. blond tobacco consumption has been more frequent in men). One could expect that those histological types more associated with tobacco smoking would be diagnosed in later stages (squamous and small cell carcinomas).[6] Recent studies have suggested that women might be more susceptible compared to men for the same lifetime smoking exposure.[7]

Some authors have observed that men were more likely to be diagnosed at a more advanced stage of lung cancer,[8] though this result was not statistically significant. In fact, there are no studies formally addressed to compare lung cancer symptoms at diagnosis by sex, and also if potential differences in the number or type of symptoms may exist comparing men and women by stage at diagnosis. This information is also lacking regarding tobacco consumption, where the presence of symptoms may be different between men and women in never-smokers and ex-smokers or current smokers at diagnosis. Having a large series of lung cancer patients diagnosed in different hospitals and in a relatively short period of time would allow to compare these characteristics by sex and provide relevant information on the possible differences at diagnosis of lung cancer patients by sex.

The aim of this study is to compare lung cancer characteristics by sex using the Spanish Thoracic Tumour Registry, with special emphasis in type and number of symptoms at diagnosis, age at diagnosis, and stage. Lung cancer cases will be classified as non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC).

We present the following article in accordance with the STROBE reporting checklist (available at