Patients’ Demographics
Table 1 presents the background data of study participants, including demographics, BMI, and smoking history, for two groups: malignant (
n = 33) and benign (
n = 33). The malignant group consists of patients with lung cancer, while the benign group is composed of patients with chronic lung disease. The mean age of the malignant group is 62.7 ± 8.7 years, with an age range of 48–75 years, while the mean age of the benign group is 58.2 ± 13.6 years, with an age range of 37–73 years. The difference in mean age between the two groups is not statistically significant (
p = 0.114), suggesting that age is not a distinguishing factor between the two groups. The mean BMI in the malignant group is 23.5 ± 4.1 kg/m
2, which is significantly lower than that of the benign group (27.3 ± 5.8 kg/m
2), with a
p-value of 0.003. When evaluating BMI categories, there is a statistically significant difference between the groups (
p = 0.030). In the malignant group, 54.5% have a BMI of 25–29.9 kg/m
2, and 39.4% have a BMI greater than 30 kg/m
2, while in the benign group, these percentages are 24.2% and 57.6%, respectively.
Gender distribution differs between the two groups, with a higher percentage of males in the malignant group (63.6%) than in the benign group (42.4%), but the difference is not statistically significant (p = 0.084). The percentage of smokers or ex-smokers is higher in the malignant group (60.6%) compared to the benign group (48.5%), but this difference is also not statistically significant (p = 0.322). However, there is a significant difference in pack-year smoking history between the two groups (p < 0.001), with a median of 34.0 pack-years (interquartile range 22.5–41.0) in the malignant group, compared to a median of 18.5 pack-years (interquartile range 12.0–29.5) in the benign group. This indicates that the malignant group has more exposure to smoking than the benign group. Finally, exposure to respiratory hazards is comparable between the two groups, with 42.4% of the malignant group and 51.5% of the benign group reporting exposure, and no statistically significant difference was observed (p = 0.459).
Table 2 presents the clinical data and investigation results of study participants, comparing patients with lung cancer and those with chronic lung disease. In terms of clinical data, the prevalence of coughing is similar between the two groups (87.9% in the malignant group and 78.8% in the benign group), with no statistically significant difference (
p = 0.321). The percentage of dry cough also shows no significant difference between the groups (69.0% in the malignant group and 65.4% in the benign group,
p = 0.777). Thoracic pain is more common in the malignant group (30.3%) than the benign group (6.1%), with a statistically significant difference (
p = 0.010). Hemoptysis, fever, and dyspnea show no significant differences between the groups (
p = 0.281,
p = 0.302, and
p = 0.353, respectively).
Weight loss was significantly more prevalent in the malignant group (69.7%) compared to the benign group (6.1%, p < 0.001). In contrast, anorexia was exclusively observed in the benign group (54.5%) and absent in the malignant group, with a highly significant difference (p < 0.001). Fatigue was reported by 90.9% of the malignant group and 78.8% of the benign group, with no significant difference (p = 0.969). Wheezing and stridor were more prevalent in the benign group (51.5%) compared to the malignant group (15.2%), with a significant difference (p = 0.002). Pulmonary auscultation results showed no significant difference between the groups (p = 0.083). The mean duration of symptom onset is significantly shorter in the malignant group (5.6 ± 3.7 months) compared to the benign group (15.2 ± 10.4 months, p < 0.001). For spirometry investigation results, there was a significant difference in the distribution of patterns (p < 0.001). The malignant group showed a higher prevalence of obstructive (33.3%) and mixed patterns (42.4%), while the benign group had a higher prevalence of restrictive patterns (45.5%). Regarding the degree of respiratory dysfunction (FEV1), there was no significant difference between the groups (p = 0.173).
The bronchoalveolar lavage fluid analysis presented in
Table 3 includes findings from a multiplex PCR assay, culture media, and cytology. In the multiplex PCR assay, there was no significant difference in the presence of commensal flora,
Pseudomonas aeruginosa,
Streptococcus spp.,
Klebsiella spp.,
Staphylococcus aureus, or
Escherichia coli between the malignant and benign groups (
p-values ranging from 0.076 to 0.741). On the multiplex PCR assay,
Acinetobacter spp. was identified in a significantly higher proportion of patients with lung cancer (15.2% vs. 0.0%). In addition, there was a significant difference in the presence of
Candida spp. and Parainfluenza virus between the two groups.
Candida spp. was more prevalent in the benign group (24.2%) compared to the malignant group (6.1%,
p = 0.039). Parainfluenza virus was only detected in the malignant group (12.1%) and not found in the benign group (
p = 0.039). In the culture media analysis, there was no significant difference in the presence of commensal flora,
Pseudomonas aeruginosa,
Streptococcus spp.,
Acinetobacter spp.,
Klebsiella pneumoniae,
Staphylococcus aureus, or
Escherichia coli between the malignant and benign groups (
p-values ranging from 0.150 to 1). The presence of
Candida spp. was not significantly different between the malignant group (9.1%) and the benign group (21.2%,
p = 0.169).
Cytology results showed significant differences in the presence of atypical cells, tumoral cells, and lymphocytes between the two groups. Atypical cells were more prevalent in the malignant group (39.4%) compared to the benign group (12.1%, p = 0.011). Tumoral cells were found exclusively in the malignant group (30.3%) and were not detected in the benign group, with a highly significant difference (p < 0.001). Lymphocytes are more prevalent in the benign group (69.7%) compared to the malignant group (24.2%, p < 0.001). There was no significant difference in the presence of neutrophils between the groups (p = 0.121), while eosinophils showed a significant difference, being more prevalent in the benign group (51.7%) compared to the malignant group (36.4%, p = 0.010).
Table 4 presents the scale and survey results comparing patients with lung cancer and those with chronic lung disease at both the initial and follow-up time points. The scales and surveys include the Eastern Cooperative Oncology Group (ECOG) performance status, Karnofsky scale, General Anxiety Disorder-7 (GAD-7), and Patient Health Questionnaire-9 (PHQ-9). At the initial time point, the malignant group had a significantly higher mean ECOG score (2.34 ± 0.66) compared to the benign group (1.92 ± 0.24,
p = 0.001), indicating a lower performance status. The mean Karnofsky score was significantly lower in the malignant group (71.36 ± 8.68) compared to the benign group (79.34 ± 6.18,
p < 0.001), suggesting a poorer functional status. The mean GAD-7 score was significantly higher in the malignant group (7.18 ± 2.41) compared to the benign group (5.45 ± 3.52,
p = 0.023), indicating more severe anxiety symptoms. The mean PHQ-9 score was also significantly higher in the malignant group (4.90 ± 2.29) than in the benign group (3.45 ± 2.84,
p = 0.026), implying more severe depression symptoms.
At the follow-up time point, the malignant group continued to have a significantly higher mean ECOG score (2.08 ± 0.52) than the benign group (1.71 ± 0.39,
p = 0.002). The mean Karnofsky score remained significantly lower in the malignant group (75.12 ± 8.07) compared to the benign group (82.60 ± 6.49,
p < 0.001). The mean GAD-7 score remained significantly higher in the malignant group (6.61 ± 2.25) compared to the benign group (5.07 ± 3.14,
p = 0.035). However, there was no significant difference in the mean PHQ-9 score between the malignant group (4.27 ± 2.06) and the benign group (3.91 ± 1.95,
p = 0.468) at the follow-up time point, as presented in
Figure 1.
Table 5 presents the results of the Hospital Anxiety and Depression Scale (HADS) questionnaire for patients with lung cancer and those with chronic lung disease at the time of diagnosis and at follow-up. The HADS questionnaire measures levels of anxiety and depression, with higher scores indicating greater levels of anxiety or depression. At the time of diagnosis, the mean anxiety score in the malignant group was 7.6 ± 4.1, while the benign group had a mean score of 6.7 ± 3.5. The difference between the two groups was not statistically significant (
p = 0.341). In contrast, the mean depression score was 7.2 ± 3.6 in the malignant group and 5.3 ± 2.3 in the benign group, with a statistically significant difference between the two groups (
p = 0.013). The total HADS score was significantly different between the malignant group (12.8 ± 6.3) and the benign group (10.1 ± 4.2,
p = 0.044), as presented in
Figure 2.
At follow-up, the mean anxiety score for the malignant group was 6.9 ± 4.7, and the benign group had a mean score of 6.2 ± 4.5. No statistically significant difference was found between the groups (
p = 0.538). The mean depression score was 6.8 ± 3.1 in the malignant group and 5.1 ± 4.8 in the benign group, with no significant difference between the groups (
p = 0.092). The total HADS score was not significantly different between the malignant group (11.4 ± 5.5) and the benign group (9.8 ± 6.1,
p = 0.267). Lastly, there was no significant association found between bronchial microbiota and depression, as measured on the PH-9 survey (
Table 6).