Aside from a thorough history and examination, certain radiographic studies are essential tools for the thoracic surgeon. A standard chest x-ray provides a good overview—it can show larger lesions and may even show sequelae of smaller lesions such as effusions or postobstructive atelectasis. Different projections can offer additional information. Computed tomography (CT) enables visualization of smaller lesions and helps determine size, location, depth, and relation to other structures. Magnetic resonance imaging (MRI) is limited to assessing neural involvement or differentiating mediastinal structures; it does not usually offer more information than a CT. It is more often used for the evaluation of brain metastases. Positron emission tomography (PET) has become the standard for staging thoracic malignancies because it is more accurate than conventional imaging in detecting metastatic disease.¹

Lung Cancer

Tumors within the lung parenchyma may arise from primary lung etiologies or because of metastatic disease. The focus of this section will remain on primary lung cancers, for which nonsmall cell and small cell cancers account for over 90%. Smoking remains the single most important risk factor for the development of lung cancer, increasing risk 20-fold compared with nonsmokers. Other risk factors include radiation, other environmental toxins, and pulmonary fibrosis that have synergistic effects.²

Most patients are asymptomatic and develop symptoms once locally advanced or metastatic disease is present. Typicalsymptoms can include cough, hemoptysis, chest pain, or dyspnea. Involvement of local structures can result in specific symptoms, such as hoarseness (because of recurrent laryngeal nerve invasion), superior vena cava (SVC) syndrome (facial and upper extremity swelling because of SVC obstruction), and Pancoast syndrome (shoulder pain and Horner syndrome because of superior sulcus tumor invasion).

CT imaging has revolutionized the detection of lung cancer, allowing the discovery of smaller tumors and, consequently, enabling the treatment of earlier stage disease. The International Early Lung Cancer Action Program showed that 85% of patients diagnosed with lung cancer during screening were clinical stage I disease, and that those patients who underwent surgical resection within 1 month of diagnosis had an estimated 10-year survival of 92%.³ As a result, lung cancer screening has been deemed essential in the diagnosis and treatment of lung cancers such that it is recommended for patients aged 55 to 80 years with a 30-pack-year smoking history by the U.S. Preventive Services Task Force.

Diagnosis can only be confirmed with a tissue biopsy. Surgical biopsy has historically been performed, but, in more recent times, an initial biopsy is performed less invasively with a needle via either a transbronchial or transthoracic approach. Once a malignant diagnosis is obtained, decision on appropriate therapy is driven by the clinical stage. Lung cancer staging is based on the tumor node metastasis (TNM) classification (Table 4.1). In addition to PET imaging and MRI when clinically indicated to evaluate the presence of tumor spread, mediastinal staging may be necessary. This has classically been achieved with mediastinoscopy, but endobronchial ultrasound has seen increased utilization because of its less invasiveness and its ability to assess N1 nodes as well.

Once the decision to proceed with surgery has been made, the extent of resection and surgical approach must be considered. Lobectomy has been considered the gold standard technique for resection. The Lung Cancer Study Group reported increased locoregional recurrence rate and a trend toward decreased survival with limited resection versus lobectomy in 1995⁴ (Fig. 4.1). However, with the advent of lung cancer screening and the discovery of smaller cancers, this is being challenged, as more recent studies suggest no significant differences in recurrence rates and overall survival.⁵ The authors consider performing a sublobar resections in patients with small (<2 cm), anatomically feasible cancers with low standardized uptake value (Fig. 4.2). Extended resections may be required in the setting of locally advanced disease, such as chest wall invasion (Fig. 4.3) or invasion of the great vessels.

Thoracotomy is the standard approach for lung resection. However, minimally invasive techniques such as video-assisted thoracoscopic surgery (VATS) and robotic surgery are increasingly being used. Minimally invasive surgery offers short-term benefits, such as less pain, shorter hospital stays, and fewer complications.^6,7 VATS also appears to offer improved long-term outcomes.⁸

Morbidity after lung cancer surgery is approximately 35%,^9,10 with the risk of major adverse events 9.1%.¹¹ Cardiac and pulmonary events are the predominant complications seen. Several risk models have been developed to try to predict perioperative risk for patients.¹² Perioperative mortality is 1.5% to 2.5%.

Esophageal Cancer

Esophageal cancer is the most common primary esophageal malignancy. Squamous cell carcinoma is more prevalent worldwide, with its strong association with smoking and alcohol, but adenocarcinoma is more common in the United States, with the rise of obesity, gastroesophageal reflux disease, and Barrett metaplasia. Because the esophagus traverses through three anatomic domains—the neck, chest, and abdomen—determining the location of the cancer is essential in guiding treatment. Cervical esophageal cancers are primarily treated with chemotherapy and radiation. Middle and lower esophageal cancers are offered multimodality therapy consisting of surgery, chemotherapy, and radiation.

Patients commonly present with dysphagia and weight loss. Diagnosis is obtained with endoscopy. Direct visualization provides information, such as size and location of the mass, and tissue diagnosis is obtained with biopsy forceps. Once the diagnosis is confirmed, clinical stage must be determined (Table 4.2). In esophageal cancer, depth of radial invasion is more important than size in staging. Therefore determining T and N staging is best achieved with endoscopic ultrasound (EUS). Tissue biopsy via ultrasound-guided fine needle aspiration (FNA) can also be performed on suspicious lymph nodes. EUS and EUS-FNA have high sensitivity and specificity in accurately diagnosing T stage and N stage, respectively.¹³ However, T2 lesions remain notoriously challenging with an accuracy of approximately 30% because both tumor upstaging and downstaging can occur¹⁴ (Fig. 4.4). Bronchoscopy may be necessary to rule out airway invasion.

Table 4.2

Esophageal Cancer Staging TNM Classification (8th Edition)

4.2A
Category	Criteria
T category
TX	Tumor cannot be assessed
T0	No evidence of primary tumor
Tis	High-grade dysplasia, defined as malignant cells confined by the basement membrane
T1	Tumor invades the lamina propria, muscularis mucosae, or submucosa
T1aa	Tumor invades the lamina propria or muscularis mucosae
T1ba	Tumor invades the submucosa
T2	Tumor invades the muscularis propria
T3	Tumor invades adventitia
T4	Tumor invades adjacent structures
T4aa	Tumor invades the pleura, pericardium, azygos vein, diaphragm, or peritoneum
T4ba	Tumor invades other adjacent structures, such as aorta, vertebral body, or trachea
N category
NX	Regional lymph nodes cannot be assessed
N0	No regional lymph node metastasis
N1	Metastasis in 1–2 regional lymph nodes
N2	Metastasis in 3–6 regional lymph nodes
N3	Metastasis in 7 or more regional lymph nodes
M category
M0	No distant metastasis
M1	Distant metastasis
Adenocarcinoma G Category
GX	Differentiation cannot be assessed
G1	Well differentiated, >95% of tumor is composed of well-formed glands
G2	Moderately differentiated, 50% to 95% of tumor shows gland formation
G3b	Poorly differentiated. Tumors composed of nest and sheets of cells with <50% of tumor demonstrating glandular formation.
Squamous cell carcinoma G category
GX	Differentiation cannot be assessed
G1	Well differentiated. Prominent keratinization with pearl formation and a minor component of nonkeratinizing basal-like cells. Tumor cells are arranged in sheets, and mitotic counts are low.
G2	Moderately differentiated. Variable histologic features, ranging from parakeratotic to poorly keratinizing lesions. In general, pearl formation is absent.
G3c	Poorly differentiated. Consist predominantly of basal-like cells forming large and small nests with frequent central necrosis. The nests consist of sheets or pavement-like arrangements of tumor cells, and occasionally are punctuated by small numbers of parakeratotic or keratinizing cells.
Squamous cell carcinoma L categoryd
LX	Location unknown
Upper	Cervical esophagus to lower border of azygos vein
Middle	Lower border of azygos vein to lower border of inferior pulmonary vein
Lower	Lower border of inferior pulmonary vein to stomach, including esophagogastric junction
4.2B
cStage Group	cT	cN	cM
Squamous cell carcinoma
0	Tis	N0	M0
I	T1	N0-1	M0
II	T2	N0-1	M0
	T3	N0	M0
III	T3	N1	M0
	T1–3	N2	M0
IVA	T4	N0–2	M0
	T1–4	N3	M0
IVB	T1–4	N0–3	M1
Adenocarcinoma
0	Tis	N0	M0
I	T1	N0	M0
IIA	T1	N1	M0
IIB	T2	N0	M0
III	T2	N1	M0
	T3–4a	N0–1	M0
IVA	T1–4a	N2	M0
	T4b	N0–2	M0
	T1–4	N3	M0
IVB	T1–4	N0–3	M1

^aSubcategories.^bIf further testing of “undifferentiated” cancers reveals glandular components, categorize as adenocarcinoma G3.^cIf further testing of “undifferentiated” cancers reveals squamous cell components, or if after further testing they remain undifferentiated, categorize as squamous cell carcinoma G3.^dLocation is defined by epicenter of esophageal tumor.

From Rice TW, Patil DT, Blackstone EH. 8^th edition AJCC/UICC staging of cancers of the esophagus and esophagogastric junction: application to clinical practice. Ann Cardiothorac Surg. 2017;6(2):119–130.

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