Outcome of advanced lung cancer with central airway obstruction versus without central airway obstruction.

Patients with central airway obstruction (CAO) from advanced lung cancer present with significant morbidity and are assumed to have lower survival. Hence, they are offered only palliative support. We asked if patients who have advanced lung cancer with CAO (recanalised and treated) will behave similarly to those with advanced lung cancer without CAO. This study was a retrospective review of the medical records of the patients managed for advanced lung cancer during 2010 and 2015 at our institution. 85 patients were studied. Median survival and 1-, 2- and 5-year survival were 5.8 months, 30.3%, 11.7% and 2.3% versus 9.3 months, 35.7%, 9.6% and 4.7%, respectively, in the CAO and no CAO groups (p=0.30). More patients presented with respiratory failure (15 (35%) versus none; p=0.0001) and required assisted mechanical ventilation (10 (23.3%) versus none; p=0.001) in the CAO group compared with the no CAO group. Fewer patients received chemotherapy in the CAO group (11 (25.5%)) compared with the no CAO group (23 (54.7%); p=0.008). There was no difference in survival among patients with advanced lung cancer whether they presented with CAO or without CAO. Survival was similar to those without CAO in patients with recanalised CAO despite greater morbidity and lesser use of chemotherapy, strongly advocating bronchoscopic recanalisation of CAO. These findings dispel the nihilism associated with such cases.

Introduction

Among all cancer related deaths, lung cancer carries the highest mortality rate globally [1]. Advanced stage (stage III and IV) at presentation is considered the factor responsible for this high mortality [2]. Extra-thoracic feature suggesting advanced stage of lung cancer is distant metastasis. Intra-thoracic features suggestive of advanced lung cancer are mediastinal infiltration with central airway obstruction (CAO), malignant pleural effusion (MPE) with or without pleural nodularity, mediastinal involvement by discreet lymph node enlargement ipsilateral or contralateral to the primary lesion, or satellite lesion in the contralateral lung [3]. Among these features, CAO is potentially the most symptomatic form of advanced lung cancer.

30% of patients with advanced lung cancer experience CAO [4]. They often present with stridor, atelectasis, pneumonia, dyspnoea, respiratory failure requiring assisted mechanical ventilation and haemoptysis [4]. Up to 40% of lung cancer deaths may be attributable to such loco-regional disease [5]. Lung cancer associated with CAO is associated with a very poor prognosis. Median survival in patients having lung cancer and malignant CAO requiring recanalisation is 8.4 months [6]. As a result, such patients are offered only palliative support, with assumed lower survival compared with those with no CAO [7].

However, to our knowledge, there is only one study comparing survival in advanced lung cancer patients with recanalised CAO versus those with no CAO [6]. As improvement in cancer targeted therapy such as the advent of epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) has improved survival in patients with advanced non-small cell lung cancer (NSCLC), we investigated if patients with malignant CAO treated with recanalisation followed by cancer targeted therapy would behave in a similar manner as patients without CAO who are treated with cancer targeted therapy alone. Hence, we conducted the current study to compare the differences in survival among patients having advanced lung cancer with CAO (recanalised and treated), and treated advanced lung cancer without CAO.

Methods

We retrospectively reviewed patients receiving treatment for advanced lung cancer between 2010 and 2015 at our centre. Variables such as demographic data, presenting symptoms, histology, stage, therapy, intervention for airway recanalisation, techniques of recanalisation, such as laser therapy and stent placement, and survival were collected. All patients with advanced (stage III and IV) lung cancer who received anti-cancer therapy in the form of combined chemo-radiotherapy or chemotherapy alone, radiotherapy alone or tyrosine kinase inhibitors (TKIs) were included.

126 patients were treated for advanced lung cancer. Based on intra-thoracic features, we divided the patient with advanced lung cancer into two subgroups: mediastinal infiltration with CAO requiring recanalisation (group A) and advanced lung cancer without CAO (group B). Patients with advanced lung cancer by virtue of malignant pleural effusion were excluded from analysis. 43 had malignant CAO requiring recanalisation (A) and 42 did not have CAO (B).

Flexible and rigid bronchoscopies were performed using standard techniques [2]. Neodymium-doped yttrium aluminium garnet (Nd-YAG) laser photoresection (Laser sonic Model 8000; Heraeus Surgical, Milpitas, CA, USA) was performed using 15–30 watts and pulse duration of 0.5–1.0 s. In cases with extrinsic compression from malignant obstruction, ultra-flex self-expanding covered metal stents (SEMS) were deployed using standard technique. Approval was obtained from the institutional review board.

Statistical analysis

We used software (SPSS, version 17; SPSS, Chicago, IL, USA) for all statistical analyses. The results were compared using a Wilcoxon two-sample test or Fisher exact test. p-values were two sided and considered indicative of a significant difference if <0.05.

Results

85 patients with advanced stage lung cancer were studied. Age, sex, race, presenting features, histology, stage distribution and survival is presented in table 1.

TABLE 1

Characteristics of treated advanced lung cancer (n=85)

Age year	67 (48–84)
Sex male	60 (70.6%)
Race
Chinese	77 (90.5%)
Malay	6 (7.0%)
Indian	2 (2.3%)
Advanced lung cancer with CAO requiring re-canalisation	43 (50.6%)
Advanced lung cancer without CAO	42 (49.4%)
Presenting symptom
Cough	42 (49.4%)
Dyspnoea	39 (45.8%)
Respiratory failure	15 (17.6%)
Intubation for respiratory failure	10 (11.7%)
Haemoptysis	19 (22.3%)
Hoarseness	3 (3.5%)
Histology
Adenocarcinoma	30 (35.2%)
Squamous cell carcinoma	19 (22.3%)
Non-small cell lung cancer	17 (20%)
Small cell carcinoma	10 (11.7%)
Sarcomatoid carcinoma	3 (3.5%)
Others	5 (5.8%)
Stage
Stage IIIA	14 (16.4%)
Stage IIIB	13 (15.2%)
Stage IV	58 (68.2%)
Recanalisation	43 (50.6%)
Laser resection	25 (29.4%)
Stent placement	17 (20%)
Both	3 (3.5%)
Cancer specific therapy
Epidermal growth factor receptor mutation Exon 19 and 21	8 (9.4%)
Chemotherapy	34 (40%)
Radiotherapy	41 (48.2%)
TKI	13 (15.2%)
Survival
Deaths	72 (84.7%)
Survival months	9.4 (0.8–79.4)
<3 months	22 (25.8%)
≥3 months	63 (74.1%)
≥6 months	55 (64.7%)
≥12 months	31 (36.4%)
>24 months	8 (9.4%)
≥5 years	4 (4.7%)

Data are presented as median (range) unless otherwise stated. CAO: central airway obstruction; TKI: tyrosine kinase inhibitors.

Most patients were males (70.6%). Cough (49.4%) and dyspnoea (45.8%) were the most common symptoms, and lung adenocarcinoma was the most common (35.2%) histological subtype of lung cancer. 34 (40%) and 41 (48.2%) patients received chemotherapy and radiotherapy, respectively, in the whole group. Out of the 34 patients receiving chemotherapy, 11 (25.5%) had CAO and 23 (54.7%) did not (p=0.008). Among 41 patients receiving radiotherapy, 20 (46.5%) had CAO and 21 (50%) did not (p=0.82). Median survival was 9.4 (0.8–79.4) months in the whole group. 1-year, 2-year and 5-year survival was 36.4%, 9.4% and 4.7%, respectively.

Subgroup analysis of CAO versus no CAO (group A versus group B)

In the subgroup analysis of group A and group B, there was no difference in demographic features, stage of cancer or survival table 2. However, more patients in group A presented with dyspnoea, respiratory failure and haemoptysis due to CAO (p=0.0001). Squamous cell carcinoma was the common histological sub-type in this group (p=0.001) and fewer patients received chemotherapy (p=0.008). Median survival was statistically insignificant, 5.8 (0.32–62) months versus 9.3 (0.8–78.3) months, p=0.30 in patients with CAO and without CAO respectively figure 1. 1-year, 2-year and 5-year survival rate were 30.3%, 11.7% and 2.3%, respectively, in the CAO group versus 35.7%, 9.6% and 4.7%, respectively, in patients without CAO without any significant difference among the two groups (table 2).

TABLE 2

Subgroup analysis of advanced lung cancer with CAO (n=43) or without CAO (n=42): demographic features, presenting features, histology, stage, therapy and outcomes

	Treated advanced lung cancer
	With CAO requiring re-canalisation	Without CAO	p-value
Age years	63 (32–86)	67 (48–84)	0.49
Sex male	32 (74.4%)	30 (71.4%)	0.81
Pleural effusion
Central airway obstruction	43 (100%)		0.0001
Presenting symptom
Cough	17 (39.5%)	25 (59.6%)	0.08
Dyspnoea	25 (58.1%)	14 (33.3%)	0.02
Respiratory failure	15 (35%)		0.0001
Intubation for respiratory failure	10 (23.3%)		0.001
Haemoptysis	6 (14%)	13 (31%)	0.07
Hoarseness	0	3 (7.1%)	0.11
Histology
Adenocarcinoma	13 (30.2%)	17 (40.4%)	0.36
Squamous cell carcinoma	16 (37.2%)	3 (7.1%)	0.001
Non-small cell lung cancer	8 (18.6%)	9 (21.4%)	0.79
Small cell carcinoma	3 (6.9%)	7 (16.6%)	0.18
Sarcomatoid carcinoma	2 (4.6%)	1 (2.3%)	1.0
Others	1 (2.3%)	4 (9.5%)	0.20
Stage
Stage IIIA	10 (23.3%)	4 (9.6%)	0.14
Stage IIIB	8 (18.7%)	5 (12%)	0.54
Stage IV	25 (58.2%)	33 (78.6%)	0.06
Cancer specific therapy
Epidermal growth factor receptor mutation exon 19 and 21	4 (9.3%)	4 (9.5%)	1.0
Chemotherapy	11 (25.5%)	23 (54.7%)	0.008
Radiotherapy	20 (46.5%)	21 (50%)	0.82
TKI	4 (9.3%)	9 (21.4%)	0.14
Survival
Deaths	32 (74.4%)	40 (95.2%)	0.26
Survival months	5.8 (0.32–62)	9.3 (0.8–78.3%)	0.30
<3 months	13 (30.3%)	11 (26.2%)	1.0
≥3 months	30 (69.8%)	31 (73.9%)	0.81
≥6 months	20 (46.6%)	27 (64.3%)	0.12
≥12 months	13 (30.3%)	15 (35.7%)	0.64
>24 months	5 (11.7%)	4 (9.6%)	1.0
≥5 year	1 (2.3%)	2 (4.7%)	0.61

Data are presented as median (range) unless otherwise stated. CAO: central airway obstruction; TKI: tyrosine kinase inhibitor.

FIGURE 1

Box plot showing the comparison of survival in the sub-groups. The first box plot is showing group A (recanalised central airway obstruction) with median survival of 5.8 months in comparison to the second box plot showing group B (no central airway obstruction) with median survival of 9.3 months; p=0.30.

Discussion

We demonstrated that there was no difference in survival among patients with treated advanced lung cancer whether they presented with CAO or without CAO. This similar survival was seen despite greater morbidity and lesser use of chemotherapy in patients with re-canalized CAO group, strongly advocating bronchoscopic re-canalisation of CAO.

Survival with and without CAO

Median survival and 1-year survival rate were similar in patients with recanalised CAO and without CAO. While median survival in “untreated” advanced lung cancer is reported as 4 to 5 months with survival rate at 1 year of 10%, the median survival in patients receiving platinum-based chemotherapy for advanced lung cancer is reported as 8 to 12 months with survival rate at 1 year of 33% [8, 9]. In this context, survival rate in our cohort regardless of presence or absence of CAO was similar to the overall survival reported with platinum-based chemotherapy.

These findings are consistent with existing literature. The median survival and 1-year survival rate in our cohort of malignant CAO treated with recanalisation by bronchoscopic laser resection or stenting was 5.8 months and 30.3%, similar to 6.2 months and 25% reported by Saji et al. [10] in Japanese population, and 8.4 months and 40% reported by Chhajed et al. [6] in malignant CAO in the European population. Chhajed et al. [6] also reported similar survival between patients having advanced lung cancer with locally treated malignant CAO and those without CAO. In another study by Ross et al. [11], improvement in survival and level of function was described following Nd-YAG laser photoresection of the exophytic tumour obstructing central airways.

A greater proportion of patients in the CAO group in our cohort presented with dyspnoea, respiratory failure (requiring assisted mechanical ventilation) and haemoptysis. However, despite this, the survival was unaffected. This lack of detrimental effect of this greater morbidity at initial presentation on survival in this group invalidates the perception that these patients have poorer survival than those without CAO. The effect of bronchoscopic recanalisation on survival can be explained by the prompt reversal of the respiratory failure averting premature death and restoration of more stable clinical condition to allow opportunity for administration of subsequent therapies [10, 12–16].

Squamous cell carcinoma was the most common histology in patients with CAO in our cohort than patients without CAO in whom adenocarcinoma was more common. This is consistent with literature as squamous cell carcinoma involves the central airways preferentially and accounts for more than half of the NSCLC involving the airways [17, 18].

Fewer patients received chemotherapy in the CAO group. The reason for this is unclear. However, it is noteworthy that despite fewer patients receiving chemotherapy in the CAO group, the survival remained unaffected and similar to patients without CAO.

These findings of equivalent survival in patients with CAO compared to without CAO despite greater proportion presenting with life threatening symptoms, and fewer receiving chemotherapy speaks strongly in favour of aggressive management of patients with CAO with the provision of assisted mechanical ventilation if needed, timely re-canalisation using bronchoscopic techniques, followed by radiation therapy and/or chemotherapy.

It is known that platinum-based chemotherapy confers partial responses in approximately 30% of patients with advanced NSCLC [19, 20]. However, treatment with EGFR-TKIs is associated with higher response rates and survival in patients whose cancer demonstrates activating EGFR mutations [21-24]. Adenocarcinoma is the most common histological sub-type of lung cancer. Activating EGFR mutation targetable by the TKIs is also only observed in adenocarcinoma sub-type. Consequently, greater proportions of patients with adenocarcinoma are eligible for TKI therapy which, in turn, is associated with improved survival [24]. Furthermore, the advent of immunotherapy carries even greater promise for better outcomes. This speaks against taking conservative approach for these patients.

In conclusion, there was no difference in survival among patients with advanced lung cancer whether they presented with CAO or without CAO. Similar survival was seen in patients with recanalised CAO or without CAO despite greater morbidity and lesser use of chemotherapy in the former group, strongly advocating bronchoscopic recanalisation of CAO. These findings dispel the nihilism associated with such cases.