Types of Cancers

There are four major types of bronchogenic tumors: (1) squamous (epidermoid) cell carcinoma, (2) adenocarcinoma (including bronchial alveolar cell carcinoma), (3) large cell carcinoma, and (4) small cell (oat cell) carcinoma (see Figure 26-1). For therapeutic reasons, these bronchogenic tumors are commonly divided into the following two groups:

Each group grows and spreads in different way. For example, SCLC spreads aggressively and responds best to chemotherapy and radiation therapy. It occurs almost exclusively in smokers and accounts for over 20% of all lung cancers in the United States. NSCLC is more common and accounts for about 80% of all lung cancers in America. When confined to a small area and identified early, this type of cancer often can be removed surgically. Table 26-1 provides general characteristics of these cancer cell types, including growth rates, metastasis, and means of diagnosis. A more in-depth description of each cancer cell type follows.

Staging of Lung Cancer

Staging is the process of classifying information about cancer. The staging system describes the cancer cell type, the size of the tumor, the level of lymph node involvement, and the extent to which the cancer has spread. The patient’s prognosis and treatment depend, to a large extent, on the staging results. The system most often used for the staging of lung cancer is the TNM classification (Table 26-2). T represents the extent of the primary tumor, N denotes the lymph node involvement, and M indicates the extent of metastasis. On the basis of the TNM findings, roman numerals are used to identify stages I through IV, with 0 being the least advanced and IV the most advanced. Figure 26-2 provides five representative illustrations of the staging of lung cancer by the TNM classification system. A general overview and description of the staging process for non–small cell lung cancer and small cell lung cancer follows*:

Small Cell Lung Carcinoma

SCLC is staged differently than non–small cell cancer. Roman numerals are not used to identify the stages. Small cell lung cancer is usually classified as either limited or extensive:

• Limited: The cancer is confined to only one lung and to its neighboring lymph nodes.

• Extensive: The cancer has spread beyond one lung and nearby lymph nodes. It may have invaded both lungs, more remote lymph nodes, or other organs.

 OVERVIEW of the Cardiopulmonary Clinical Manifestations Associated with Cancer of the Lung

The following clinical manifestations result from the pathologic mechanisms caused (or activated) by Atelectasis (see Figure 9-8), Alveolar Consolidation (see Figure 9-9), and Excessive Bronchial Secretions (see Figure 9-12)—the major anatomic alterations of the lungs associated with cancer of the lung (see Figure 26-1).

CLINICAL DATA OBTAINED AT THE PATIENT’S BEDSIDE

The Physical Examination

Vital Signs

Increased Respiratory Rate (Tachypnea)

Several pathophysiologic mechanisms operating simultaneously may lead to an increased ventilatory rate:

• Stimulation of peripheral chemoreceptors (hypoxemia)

• Decreased lung compliance–increased ventilatory rate relationship

• Stimulation of the J receptors

• Pain, anxiety

Increased Heart Rate (Pulse) and Blood Pressure

Cyanosis

Cough, Sputum Production, and Hemoptysis

Chest Assessment Findings

• Crackles, rhonchi, and wheezing

CLINICAL DATA OBTAINED FROM LABORATORY TESTS AND SPECIAL PROCEDURES

Pulmonary Function Test (PFT) Findings

Relative to where the malignancy originates, the PFT results may show either obstructive or restrictive values. For example, when the malignancy obstructs major airways, the PFT values may show obstructive pathology—especially when chronic obstructive pulmonary disease (COPD) is present. However, when large amounts of pulmonary tissue, chest wall, and/or diaphragm are involved (extensive bronchioalveolar carcinoma), then the pathology may show restrictive PFT values.

Arterial Blood Gases

LOCALIZED (e.g., LOBAR) LUNG CANCER

Acute Alveolar Hyperventilation with Hypoxemia (Acute Respiratory Alkalosis)

pH	Paco2		Pao2
↑	↓	↓ (slightly)	↓

EXTENSIVE OR WIDESPREAD LUNG CANCER

Acute Ventilatory Failure with Hypoxemia (Acute Respiratory Acidosis)

pH*	Paco2	*	Pao2
↓	↑	↑ (slightly)	↓

^*When tissue hypoxia is severe enough to produce lactic acid, the pH and values will be lower than expected for a particular Paco₂ level.

Oxygenation Indices*

	Do2†		C(a-)o2	O2ER
↑	↓	N	N	↑	↓

^†The Do₂ may be normal in patients who have compensated to the decreased oxygenation status with (1) an increased cardiac output, (2) an increased hemoglobin level, or (3) a combination of both. When the Do₂ is normal, the O₂ER is usually normal.

---

^*C(a-)O₂, Arterial-venous oxygen difference; DO₂, total oxygen delivery; O₂ER, oxygen extraction ratio; , pulmonary shunt fraction; , mixed venous oxygen saturation; , oxygen consumption.

Hemodynamic Indices‡

When hypoxemia and acidemia are present, or when a tumor invades the mediastinum and compresses the superior vena cava, the following may be expected.

CVP	RAP		PCWP	CO	SV
↑	↑	↓	↓ or N	↓ or N	↓ or N
SVI	CI	RVSWI	LVSWI	PVR	SVR
↓ or N	↓ or N	↑	↓ or N	↑	N

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^‡CO, Cardiac output; CVP, central venous pressure; LVSWI, left ventricular stroke work index; , mean pulmonary artery pressure; PCWP, pulmonary capillary wedge pressure; PVR, pulmonary vascular resistance; RAP, right atrial pressure; RVSWI, right ventricular stroke work index; SV, stroke volume; SVI, stroke volume index; SVR, systemic vascular resistance.

RADIOLOGIC FINDINGS

Chest Radiograph

• Small oval or coin lesion

• Large irregular mass

• Alveolar consolidation

• Atelectasis

• Pleural effusion (see Chapter 23)

• Involvement of the mediastinum or diaphragm

A routine chest x-ray examination often provides the first indication or suspicion of lung cancer. Depending on how long the tumor has been growing, the chest x-ray film may show a small radiodense nodule (called a coin lesion) or a large irregular radiodense mass. Unfortunately, by the time a tumor is identified radiographically, regardless of its size, it is usually in the invasive stage and thus difficult to treat. Another common x-ray presentation of lung cancer is that of volume loss involving a single lobe or an individual segment within a lobe.

Because there are four major forms of lung cancer, chest x-ray findings are variable. In general, squamous cell and small cell carcinoma usually appear as a white mass near the hilar region; adenocarcinoma appears in the peripheral portions of the lung; and large cell carcinoma may appear in either the peripheral or the central portion of the lung. Figure 26-3 is a representative example of a large bronchogenic carcinoma in the right lung. Common secondary chest x-ray findings caused by bronchial obstruction include alveolar consolidation, atelectasis, pleural effusion, and mediastinal or diaphragmatic involvement. The x-ray appearance of cavity formation within a bronchogenic carcinoma is similar regardless of the type of cancer.

Clinically, a positron emission tomography (PET) scan is an excellent test to rule out a possible cancerous area identified on either a chest x-ray film or a computed tomography (CT) scan. For example, Figure 26-4 shows a chest radiograph that identifies two suspicious findings—one small nodule in the right upper lung lobe and a larger density in the left lower lung lobe, just behind the heart. Figure 26-5 shows two CT scans that also identify the two suspicious findings and their precise location. Figures 26-6, 26-7, and 26-8 show PET scans that all confirm a “hot spot” (likely cancer) in the lower left lobe. However, the PET scan shown in Figure 26-9 confirms that the nodule in the right upper lobe is benign (i.e., no hot spot is noted).

Finally, the PET/CT image provides an image of excellent quality and high sensitivity and specificity in detecting malignant lesions in the chest. Figure 26-10 shows a CT/PET scan alongside a CT scan and a PET scan; all the images show the same malignant nodule in the right upper lobe.

BRONCHOSCOPY FINDINGS

• Bronchial tumor or mass lesion

The fiberoptic bronchoscope may permit direct visualization of a bronchial tumor for further inspection, biopsy, and assessment of the extent of the disease (Figure 26-11).

COMMON NONRESPIRATORY CLINICAL MANIFESTATIONS

• Hoarseness

• Difficulty in swallowing

• Superior vena cava syndrome (distention of the neck veins and neck and facial edema)

• Weakness and weight loss

When a bronchogenic tumor invades the mediastinum, it may involve the left recurrent laryngeal nerve, the esophagus, or the superior vena cava. When the tumor involves the left recurrent laryngeal nerve, the patient’s voice becomes hoarse. When the tumor compresses the esophagus, swallowing may become difficult. When a tumor invades the mediastinum and compresses the superior vena cava, blood return to the heart from the head and upper part of the body may be interrupted. When obstruction occurs, the symptoms include an increased ventilatory rate and cough, which is greatly aggravated by recumbency. Clinically, this condition is called superior vena cava syndrome.

GENERAL COMMENTS

The clinical manifestations associated with lung cancer may be caused by local effects, tumor extensions into the mediastinum, paraneoplastic endocrine syndromes, or tumor metastases. The most common local signs and symptoms are cough, chest pain, dyspnea, and hemoptysis. Less common signs and symptoms include superior vena cava syndrome, hoarseness resulting from vocal cord paralysis, wheezing, shoulder and upper back pain, and Horner’s syndrome (constriction of the pupil and enophthalmos) related to an apical (Pancoast) tumor. Symptoms of metastatic lung cancer include bone pain, weakness, weight loss, and central nervous system signs and symptoms such as headache, seizures, or symptoms mimicking those of a cerebrovascular accident (CVA). Asymptomatic axillary and supraclavicular lymph node metastasis also may be present. Deep venous thrombophlebitis is present at the time of diagnosis in 5% to 10% of patients with lung cancer.

Surgery

Surgery is usually an option only for patients who have NSCLC that is limited to only one lung, up to stage IIIA. This is usually confirmed with a CT scan and PET scan. In addition, an adequate respiratory reserve must be present to allow good lung function after the lung tissue has been removed. Common surgical procedures include the following:

In the patient with adequate preoperative respiratory reserve (i.e., a predicted after-surgery forced expiratory volume in 1 second [FEV₁] of 0.8 to 1 L), a lobectomy is the preferred option. A lobectomy reduces the chances of local recurrence. In the patient with an inadequate respiratory reserve, a wedge resection may be performed. The application of radioactive iodine brachytherapy at the margins of the wedge resection may minimize the need to perform a lobectomy.

Chemotherapy

Chemotherapy is the general term for any treatment involving the use of chemical agents or drugs that are selectively destructive to malignant cancer cells. Because chemotherapy can eliminate cancer cells at sites away from the original cancer, it is considered a systemic treatment. Unfortunately, because the drugs used in chemotherapy can damage healthy cells along with the cancer cells, serious side effects are common. Fast-growing cells are especially likely to be affected (e.g., cells in the digestive tract, bone marrow, and hair). In addition, the patient may experience nausea and vomiting, dizziness, fatigue, and increased risk of infection.

The primary treatment for SCLC is chemotherapy and radiation; surgery is usually not an option. Chemotherapy is also administered to patients with metastatic NSCLC. The type of chemotherapy is based on the tumor category. SCLC is commonly treated with cisplatin and etoposide. Combinations of carboplatin, gemcitabine, paclitaxel, vinorelbine, topotecan, and irinotecan are also commonly used. NSCLC is commonly treated with cisplatin or carboplatin, in combination with gemcitabine, docetaxel, etoposide, or vinorelbine.

Radiation Therapy

Radiation therapy (external radiation) is often given with chemotherapy. It may be used with curative intent in patients with NSCLC who are not eligible for surgery. This type of high-intensity radiation therapy is called radical radiotherapy. In the patient with potentially curable SCLC, radiation therapy and chemotherapy are commonly recommended. In both NSCLC and SCLC, a smaller dose of radiation therapy is often used for symptom control (called palliative radiotherapy). Brachytherapy (localized radiotherapy) may also be used when the tumor can be visualized with a bronchoscopy. Brachytherapy entails the use of small radioactive rods (called seeds) that are implanted near or directly into the tumor.

In the patient with limited-stage SCLC, prophylactic cranial irradiation (PCI) to the brain is often given. PCI is used to minimize the risk of cancer cell metastasis to the brain. Recent advances in targeting and imaging have led to the development of stereotactic radiation therapy (also called stereotactic external-beam radiation therapy and stereotaxic radiation therapy). This type of therapy uses special equipment to position the patient and precisely deliver radiation to a tumor. The total radiation dose is delivered in a small number of doses over several days. It is primarily used in patients who are not surgical candidates.

The goal of radiation therapy is to kill cancer cells without hurting normal tissue cells. Side effects of radiation therapy include redness, swelling, sloughing of skin at the point at which the radiation enters the patient’s body, an increased risk of infection, and radiation fibrosis of adjacent lung tissue. In addition, the patient may experience nausea, vomiting, change of taste, fatigue, and malaise.

Comfort (Supportive) Care

Radiation therapy and chemotherapy may not be tolerated when the patient has extensive small cell lung cancer and is in poor health. The patient may choose to receive only comfort or palliative care, which means treating the symptoms of the cancer rather than the cancer itself.

Oxygen therapy is used to treat hypoxemia, decrease the work of breathing, and decrease myocardial work. Because hypoxemia is associated with lung cancer, supplemental oxygen may be required. However, capillary shunting is common because of the alveolar compression and consolidation often produced by lung cancer. Hypoxemia caused by capillary shunting often is refractory to oxygen therapy (see Oxygen Therapy Protocol, Protocol 9-1).

Physical Examination

The respiratory care practitioner reviewed the admitting history information in the patient’s chart and found the man sitting up in bed in obvious respiratory distress. He appeared weak. His skin was cyanotic, and his face, arms, and chest were damp with perspiration. Wheezing was audible without the aid of a stethoscope. He stated in a hoarse voice that he had coughed up a cup of sputum since breakfast 2 hours earlier. He demonstrated a weak cough every few minutes or so. His cough was productive of large amounts of blood-streaked sputum. The viscosity of the sputum was thin. After each coughing episode, he stated that he wanted a cigarette and then laughed.

His vital signs were as follows: blood pressure 155/85, heart rate 90 bpm, respiratory rate 22/min, and temperature normal. Palpation was unremarkable. Percussion produced dull notes over the left lower lobe. On auscultation, rhonchi, wheezing, and crackles could be heard throughout both lung fields. His arterial blood gas values on a 2 L/min oxygen nasal cannula were as follows: pH 7.51, Paco₂ 29, 24, and Pao₂ 66. His oxygen saturation measured by pulse oximetry (Spo₂) was 94%. On the basis of these clinical data, the following SOAP was documented.

Respiratory Assessment and Plan

3 Days after Admission

A respiratory care practitioner evaluated the patient during morning rounds. After reviewing the patient’s chart, the practitioner went to the patient’s bedside and discovered that the man was not tolerating the chemotherapy well. He had been vomiting intermittently for the past 10 hours and was still in obvious respiratory distress. He appeared cyanotic and tired, and his hospital gown was wet from perspiration. His cough was still weak and productive of large amounts of moderately thick, clear, and white sputum. He stated in a hoarse voice that he still was not breathing very well.

His vital signs were as follows: blood pressure 166/90, heart rate 95 bpm, respiratory rate 28/min, and temperature normal. Dull percussion notes were elicited over both the right and left lower lobes. Rhonchi, wheezing, and crackles were auscultated throughout both lung fields. His ABG values were as follows: pH 7.55, Paco₂ 25, 23, and Pao₂ 53. His Spo₂ was 92%. On the basis of these clinical data, the following SOAP was documented.

Respiratory Assessment and Plan

16 Days after Admission

Although the physician’s original intention and hope were to discharge the patient soon, stabilizing the man for any length of time proved difficult. Over the next 2 weeks, the patient had continued to be nauseated on a daily basis. He did, however, have occasional periods of relief during which he could breathe, but he generally was in respiratory distress. On day 16 the respiratory therapist observed and collected the following clinical data.

The patient was lying in bed in the supine position. His eyes were closed, and he was unresponsive to the therapist’s questions. The patient was in obvious respiratory distress. He appeared pale, cyanotic, and diaphoretic. No cough was observed at this time, but rhonchi easily could be heard from across the patient’s room. The nurse in the patient’s room stated that the doctor had called the rhonchi a “death rattle.” The patient’s vital signs were as follows: blood pressure 170/105, heart rate 110 bpm, respiratory rate 12/min and shallow, and rectal temperature normal. Percussion was not performed. Rhonchi, wheezing, and crackles were heard throughout both lung fields. His ABG values were as follows: pH 7.28, Paco₂ 63, 28, and Pao₂ 66. His Spo₂ was 89%. At that time, the following SOAP was recorded.

Respiratory Assessment and Plan

Discussion

This case demonstrates the few specific treatments that a respiratory care practitioner can bring to the care of patients with lung cancer. Specifically, it illustrates that most of the patients have concomitant obstructive pulmonary disease with a need for good Bronchopulmonary Hygiene Therapy (see Protocol 9-2). The patient’s comfort must be kept in mind at all times.

The first assessment was performed soon after bronchoscopy and diagnosis. The patient’s blood-stained sputum could have reflected the primary tumor or, as likely, bleeding from the bronchoscopy sites. In such cases the practitioner must monitor this sputum as the days go along. No improvement in the patient’s wheezing can be expected if a bronchial tumor is the cause, but it may improve if bronchospasm (from cigarette smoking) is the causative factor.

The rhonchi, wheezing, and crackles indicated the need for vigorous bronchial hygiene therapy. The atelectasis in the left lower lobe suggested that a trial of careful Lung Expansion Therapy Protocol (Protocol 9-3) was in order (see Figure 9-8). The ABG values assessed with the patient on 2 L/min O₂ showed acute alveolar hyperventilation with moderate hypoxemia. A trial of oxygen by Venturi mask (or nonrebreathing mask) would be helpful. Patient anxiety may be alleviated with appropriate treatment of the hypoxemia.

The second assessment revealed that the patient may have developed atelectasis in both the right and left lower lobes (where the tumor masses had been noted previously). This case may present a setting in which therapeutic bronchoscopy or laser-assisted endobronchial resection of the tumor masses may be helpful. The patient continued to be hypoxemic, despite alveolar hyperventilation. A higher Fio₂ (for example, through a Venturi oxygen mask) was indicated. Vigorous suctioning was appropriate. Because of the impending ventilatory failure, ordering at least one cycle of ventilator support for such a patient would not be surprising, given that the patient had just recently received radiation and chemotherapy. The patient’s wishes in this respect should have been checked against his living will or durable power of attorney for health care, if such a document existed.

The last assessment indicates that the patient did not elect aggressive therapy and that he had slipped into acute ventilatory failure. All health-care personnel had agreed that the patient was close to death. The practitioner may be excused for not suggesting the use of chest physical therapy and postural drainage at this time, because of the patient’s wishes. Aerosolized morphine is now being used to relieve dyspnea in terminally ill cancer patients. If, however, aggressive therapy were still in order, formal evaluation and treatment of superimposed atelectasis or pneumonia, or both, would be in order.