The original chart review included information on 118 patients. We removed three patients who did not meet the selection criteria. The final sample size analyzed was 115 patients from three tertiary-level public hospitals (see patient flow chart, Fig. 1).
Most of the patients were treated at the INER (n = 94; 81.7%), followed by the Social Security Institute of the State of Mexico and Municipalities (ISSEMYM) (n = 16; 13.9%), and the IJC (n = 5; 4.4%).
Demographic and Clinical Characteristics
The median age was 61.0 years (IQR 52.4–68.5), and 51.3% were female. The median weight at diagnosis was 63 kg (IQR 53.5–73). The maximum level of education reported was generally low: no schooling 10.4%; primary school (age 6–12 years) 30.4%; secondary school (age 12–14 years) 13.0%; high school 11.3%; university 8.7%; other 25.2%; unknown 0.9%. Most patients (60.9%) reported comorbidities. Of these, 38.6% reported diabetes mellitus, 7.1% obesity, and 50% cardiovascular diseases. All other comorbidities impacted < 5% of the sample.
The most common type of NSCLC was non-squamous (92.2%), and the most typical histology was adenocarcinoma (88.7%). Almost all patients were stage IV (97.4%) at first diagnosis. Half of the population had a history of smoking (49.6%), 43.48% had positive wood smoke exposure, and almost all had a negative family history of NSCLC (97.4%) (Table 1).
Almost all patients had metastases at the time of diagnosis (99.1%). The sites of metastasis location were lung (54 patients; 47.4%), followed by bone (36; 31.6%), brain (11; 9.7%), and distant lymph nodes (eight; 7%).
EGFR mutation was tested in only 85 (73.9%) patients, 31 (36.5%) of which were positive. Anaplastic lymphoma kinase (ALK) translocation was tested in 13 (11.3%) patients, two (15.4%) of which were positive. Patients had a median waiting time of 24 days (IQR 15.0–35.0) from diagnosis to first-line treatment.
All patients received first- and second-line therapy (in accordance with the selection criteria), and 54.8% completed a third-line, 27.8% a fourth-line, 7.8% a fifth-line, 2.6% a sixth-line, and 1.7% a seventh-line active therapy (Table 2).
Only 32.2% of the patients received radiotherapy after diagnosis of NSCLC.
Within the 13 regimens observed in the first line of treatment, the carboplatin–paclitaxel combination was administered in 65.2% of the observed population. Ten different therapeutic agents were identified, and most patients were initially treated with platinum-based chemotherapy (87.8%) and paclitaxel (67.8%). Most of the first-line treatments (93.6%) were administered on an outpatient basis. Three patients (2.6%) achieved complete response (CR), 46 (40%) had partial response (PR), 24 (20.9%) had stable disease (SD), and the rest experienced progression or died.
Among the 13 therapeutic agents administered within the different second-line regimens, four were administered to > 15% of the patients, either as monotherapy or combined: docetaxel to 47.0%, carboplatin to 25.2%, paclitaxel to 15.7%, and nintedanib to 15.7%. Nivolumab was administered to 8.7% of the patients. A large proportion of the second-line treatments (80.4%) were administered on an outpatient basis. Two patients (1.7%) achieved CR, 27 (23.5%) had a PR, 35 (30.4%) had SD, and the rest (44%) experienced progression or died.
Only 63 (55%) patients completed third-line therapy, where carboplatin was the most frequently used drug (28.6%), followed by paclitaxel (25.4%), nivolumab (20.6%), and docetaxel (17.5%). No patient achieved CR, seven patients (11.1%) had a PR, 17 (27%) had SD, and the rest 39 (80%) showed progression or died.
In total, 30 (26%) patients received fourth-line therapy. The most frequently used therapy was docetaxel (23.3%), followed by nivolumab (16.7%) and irinotecan (13.3%). Only two (6.67%) patients achieved PR, and 20 SD (8%).
Nine (8%) patients received fifth-line therapy, three (3%) received sixth-line, and only two patients (2%) received seventh-line treatment.
In total, 59 patients (51.3%) required hospitalization during the observation period; there were 118 hospitalizations/medical emergencies in the patient population, and most of them were hospitalized more than once (76.3%), with an average length of stay of 69 days. Supportive care was most often associated with pain treatment (see Table 3 for details).
AEs occurred in 53.0% of the patients; none was fatal. Among these patients, 22 (19.1%) experienced fatigue, 12 (10.4%) diarrhea, 12 (10.4%) neuropathy, eight (6.7%) neutropenia, seven (6.1%) thrombocytopenia, and < 5% experienced other AEs.
The median cost per patient was $US7039.40, with a minimum of $US628.30 and a maximum of $US3,557,364.20. Estimated therapy costs per patient, per line, and per month are shown in Table 4.
Median OS for the overall cohort (n = 115) was 12 months (95% CI 9.8–14.1). The Kaplan–Meier plot for patient OS is shown in Fig. 2.