Docetaxel/Cisplatin: Docetaxel 75 mg/m2, and cisplatin 75 mg/m2, both on day 1, every 21 days. Total cycles: 4.

Experimental group, according to the BRAC1 levels of the tumor tissue, one of the following treatments will be assigned:

• Low expression of BRCA1 gemcitabine 1250 mg / m2, days 1 and 8, and cisplatin 75 mg / m2, day 1. Cycles every 21 days. Total cycles: 4
• Intermediate expression levels of BRCA1 docetaxel 75 mg / m2, and cisplatin 75 mg / m2, both administered on day 1, every 21 days. Total cycles: 4.
• High expression levels of BRCA1 docetaxel 75 mg / m2, day 1. Cycles every 21 days. Total cycles: 4.

Total of all reporting groups

T: Tumour's Classification by Size

T1= Tumour < 3 cm in greatest dimension, surrounded by lung or visceral pleura, without bronchoscopic evidence of invasion more proximal than the lobar bronchus T2= Tumour > 3 cm but < 7 cm or tumour

T3= Tumour > 7 cm or one that directly invades any of the following:

Chest wall, diaphragm, phrenic nerve, mediastinal pleura, parietal pericardium Tumour in the main bronchus < 2 cm distal to the carina but without involvement of the carina. Associated atelectasis or obstructive pneumonitis of the entire lung Separate tumour nodule(s) in the same lobe

N: Nodes NX:Regional lymph nodes cannot be assessed N0:No regional lymph node metastasis N1:Metastasis in ipsilateral peribronchial and/or ipsilateral hilar lymph nodes and intrapulmonary nodes, including involvement by direct extension N2:Metastasis in ipsilateral mediastinal and/or subcarinal lymph node(s) N3:Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral

Staging is a classification where cancer is located, if or where it has spread and whether it's affecting other parts of the body. There are 5 stages for NSCLC (0,I-IV)

Stage IIA: tumor larger than 4 cm but 5 cm or less in size that hasn't spread to the nearby lymph nodes.

Stage IIB: tumor that is 5 cm or less in size that has spread to the lymph nodes within the lung, called the N1 lymph nodes. A stage IIB cancer can also be a tumor more than 5 cm wide that has not spread to the lymph nodes.

Stage III: cancer spread to the lymph nodes but haven't spread to other distant parts of the body

Control group

- Docetaxel 75 mg/m2, y cisplatin 75 mg/m2, both day 1 every 21 days. Total cycles: 4.

Include participants in experimental arm

Experimental group, according to the BRAC1 levels of the tumor tissue, will be assigned one of the following treatments:

• Low expression of BRCA1 → gemcitabine 1250 mg/m2, days 1 and 8, and cisplatin 75 mg/m2, day 1. Cycles every 21 days. Total cycles: 4
• Intermediate expression levels of BRCA1 → docetaxel 75 mg/m2, and cisplatin 75 mg/m2, both administered on day 1, every 21 days. Total cycles: 4.
• High expression levels of BRCA1 → docetaxel 75 mg/m2, day 1. Cycles every 21 days. Total cycles: 4.