There are two main groups of lung cancer: “small cell lung cancer” closely linked to tobacco consumption and “non-small cell lung cancer”, mainly comprising adenocarcinomas (derived from glandular cells of the bronchi).

Adenocarcinoma is the most common type of ‘non-small cell lung cancer’ (NSCLC). It develops in the peripheral areas of the lung, especially in the upper lobes and near the pleura. Its incidence has been increasing for almost 10 years. 

Variants of adenocarcinoma

Adenocarcinomas can vary both in size and in how quickly they develop. There are mainly two variants histologically:

• acinar adenocarcinoma when it takes the form of a small sac;
• papillary adenocarcinoma, when the cells show protrusions in the shape of a glove finger.

Pulmonary adenocarcinoma

Lung adenocarcinoma primarily affects smokers. But it is also the most common type of lung cancer in women and in non-smokers.

It is the leading cause of death (all causes) in men between 45 and 64 years old in France, according to the Haute Autorité de Santé (HAS).

Tobacco consumption is by far the number one risk factor for this type of cancer. But not only. “Occupational exposures may be involved,” explains Dr Nicola Santelmo, Thoracic Surgeon at Clinique Rhéna in Strasbourg. Chemical compounds (such as asbestos, arsenic, nickel, tar, etc.) most often found at low levels in the workplace have been recognized by the International Agency for Research against Cancer as being pulmonary carcinogens for the man.

It also appears that other sources of environmental pollution are, to a lesser extent, risk factors for lung cancer, such as air pollution and radon).

The symptoms of pulmonary adenocarcinoma are often late because it does not cause particular pain. When the tumor grows, it can cause symptoms like:

• a cough or difficulty breathing if it presses on the bronchi;
• bloody sputum (sputum);
• unexplained weight loss.

“Today, however, thanks to an increasingly wide use of the scanner for screening in smoking patients, we can make the diagnosis of cancer in much earlier stages, with an indisputably better prognosis”, reassures the surgeon.

Several tests are needed to confirm the diagnosis of lung cancer.

Imagery

Imaging is essential to assess the extent of the disease:

• A “complete” CT scan (skull, thorax, abdomen and pelvis) with contrast injection if not contraindicated, provides information on the shape and size of any cancer.

The biopsy

If the radiological examinations suggest lung cancer, it is essential to take a sample of the lesion, by biopsy, to obtain histological or cytological proof. This tissue sample is usually done by endoscopy or by a puncture under scanner. Sometimes, surgery will have to be performed to take this sample: biopsy of a lymph node or a mass in the lungs.

Bronchial fibroscopy

“A bronchial endoscopy may also be necessary, especially if the tumor originates in a bronchus. It may also be necessary to obtain a sample of the tumor or of a lymph node to complete the assessment ”.

The assessment makes it possible to determine a stage of the disease, taking into account the size and location of the tumor (“T”), the existence and location of lymph nodes (“N”) and the existence or not “metastases” which are distant extensions of the lung tumor (the “M”). Two thirds of small cell bronchial carcinomas are diagnosed at the metastatic stage.

Assessment of respiratory and cardiac function

Finally, an assessment of respiratory and cardiac function is essential in order to determine whether surgical or chemotherapy treatment is possible with lower risk of complications.

“The prognosis depends on the stage of the cancer and the treatment that can be considered,” says the specialist. It varies between less than 10% at 5 years in the more advanced stages and 92% at 5 years in the early stages. The importance of early diagnosis is therefore enormous! In addition, among all the patients operated on by surgery (all stages combined) 1 in 2 patients is alive 5 years later ”.

The treatment implemented depends on the histological type of cancer, its stage (that is to say its degree of extension), the general state of health of the patient, and the decision taken collegially by a multidisciplinary medical team bringing together pulmonologist, surgeon, radiotherapist, radiologist, nuclear doctor and pathologist.

Purpose of processing

The aim of the treatment is to:

• remove the tumor or metastases;
• control the spread of pulmonary adenocarcinoma;
• prevent recurrence;
• treat the symptoms.

The different treatments

There are several types of treatment for pulmonary adenocarcinoma:

• resection surgery, removal of the entire tumor, in combination with chemotherapy, before or after the operation
• radiotherapy alone,
• chemotherapy alone,
• chemotherapy combined with radiotherapy,
• radiofrequency or stereotaxic radiotherapy which corresponds to irradiation very focused on the lung tumor,
• another systemic treatment (immunotherapy and / or targeted therapies).

“Surgical interventions today are increasingly targeted and planned on the basis of preoperative examinations and may consist of segmentectomy or pulmonary lobectomies (involving more or less important parts of the lung)”, concludes Dr Santelmo.