Lung metastasis

DR SUHAS K R

BACKGROUND 2nd most common organ for secondaries after liver

• Before effective chemotherapy up to 80% of patients treated by radical resection of the primary tumor of osteosarcoma died from lung metastasis

• More than 80% of sarcomas metastasize initially to the lung

• Upto 10-15% of colorectal ca develop lung mets post curative resection(rectum>>colon)

Number games Highest predilection MC metastasis• Choriocarcinoma – 60%

• Osteosarcoma – 15%

• Testicular tumors – 12 %

• Melanoma – 5%

• Head and neck - 5%

• Breast • Colon• Kidney• Uterus• Prostate• oropharynx

Likelihood • SLN in a patient with known extra thoracic primary – 24%

• With no primary – 3% metastatic

Type of primary SLN on x ray

Sarcoma ,melanoma Mostly metastatic

Ca breast , squamous cell ca

Mostly primary ca lung

Adeno ca Equal chances

CHARACTERISTICS

CANNON BALLS:• Neoplasms with rich vascular supply draining directly

into the systemic venous system.• Colorectal cancer and sarcoma MILIARY PATTERN:• Thyroid carcinoma • Renal cell carcinoma • Sarcoma of the bone • Trophoblastic disease

Cavitating Lesions:• Cavitation - in 4% of

metastatic deposits is more likely in squamous cell lesions.

• Colon, anus, cervix, breast and larynx account for 69% of such occurrences.

• Avascular necrosis of the lesion secondary to vascular occlusion, is the presumed mechanism for cavitation.

Calcification:o Calcification of metastasis from ovarian, thyroid,

breast and mucin producing gastrointestinal neoplasms. 

o Lung metastasis may also calcify following therapy. o Almost all calcified or ossified lung metastasis

occurring prior to therapy are due to osteosarcoma or chondrosarcoma. 

o Isolated cases - with synovial sarcoma and giant cell tumor of the bone.

Endobronchial Lesion• Endobronchial metastases - rare in comparison with

parenchymal deposits and account for 2% of patients who died from solid neoplasms.

• Diagnostic challenge: o Simulate primary bronchogenic carcinoma in clinical

presentationo X ray - bronchial obstruction and obstructive atelectasis or

pneumonia. o The endobronchial lesion - characteristic pigment on

bronchoscopy in metastatic melanoma. 

Endobronchial Lesion

• Persistent cough, hemoptysis, wheezing - may have normal chest x-rays.

• Kidney, colon, breast sarcoma and melanoma account for 67% of the cases. 

• The metastases is located subepithelially and is due to hematogenous metastases through the bronchial arteries.

• Palliative radiation or resection becomes necessary if the patient has hemoptysis or refractory obstructive pneumonitis.

Lymphadenopathy• Autopsy incidence related to various primaries range

from 20-60%.• Head and neck and genitourinary tract neoplasms

most often cause visible intrathoracic enlargement followed by malignant melanoma and breast carcinoma.

• Considered positive on CT scans by size criteria; namely, if the short axis is 1cm or greater.

• Nineteen percent of nodes from 0.5-1cm have been reported positive for micrometastases

Diagnostic challenge

o Lymphadenopathy may be hilar, mediastinal or both. o Sarcoidosis - rarely causes mediastinal nodular

enlargement without hilar enlargement.o Lymph node metastasis is not always associated with lung

metastasis. o D/D - sarcoid, non-infectious granulomatous disease,

lymphoma, leukemia or a primary mediastinal tumor. o Metastatic disease may cause bilateral hilar enlargement.

However, these patients are usually symptomatic. 

Pleural Effusion• The effusions - tend to be

massive, recurrent and associated with shortness of breath. 

• Associated with extensive underlying lung and systemic metastases. 

• Malignant effusions >50% of exudative pleural effusions. 

• Lung, breast, stomach and ovary - 81% of cases.

PLEURAL MASSES •Significant pleural masses can exist without recognition (as in the adjoining CXR), even in the absence of pleural effusion.•CT scan – investigation of choice•Thymoma, multiple myeloma and cystadenocarcinoma lung are reported to give such a metastatic pattern.

SPONTANEOUS PNEUMOTHORAX •Pneumothorax occurring secondary to pulmonary metastasis is rare.  •This mode of presentation occurs secondary to necrosis of subpleurally located metastases with the resultant bronchopleural fistula.  •Cavitating sarcoma is reported to present in this manner.

Alveolar Pattern• Alveolar form of metastases - relatively rare and unrecognized

form  • Histologically - indistinguishable from primary alveolar cell lung

carcinoma.• Pancreatic carcinoma is the most common primary • Metastatic liposarcoma and laryngeal carcinoma - occasionally• The metastatic lesions from choriocarcinoma also have features of

alveolar pattern.  o However, this is secondary to bleeding into the lesions rather

then due to tumor, per se.

Interstitial Pattern

• Less than 10% of lung metastases have a lymphangitic pattern.

• Pathogenesis:tumor spread along the perivascular lymphatics after initial deposition of tumor embolus in a pulmonary capillary by hematogenous route. 

• The stomach, lung and breast account for 80% of cases. 

• A doubling time of between 20 and 400 days is consistent with a malignant lesion. Doubling of the volume means that a nodule 0.5cm in diameter increases by 0.12cm in diameter, a nodule of 1cm increases by 0.26cm in diameter, a nodule of 2cm increases by 0.52cm in diameter, a mass of 3cm in diameter increases by 0.78cm in diameter, and so forth.

• Patterns of calcification strongly suggestive of a benign nature of a nodule are diffuse homogenous calcification, central calcification, laminated concentric calcification, and popcorn calcification.

Prognostic factorsROLE NO ROLE

• Complete resectability

• Tumor doubling time• Disease free interval• Number of nodules• Histology• Nodal status

• Age • Gender• U/L vs B/L disease• Wedge resection vs

formal lobectomy

Investigations • Cancer-specific tumor markers

• Chest Radiographyo potential to overlook lesions located in the lung apices

or posterior sulci or against the heart or mediastinumo 25% of the total lung volume is not readily accessible for

visual examination using plain posteroanterior chest radiography.

CT SCAN• CT is the most effective method of imaging lung metastasis

• 80 - 95% sensitivity of helical CT in detecting pulmonary nodules of 6 mm or greater but only 69% with nodules less than 6 mm

• Surveillance - every 3 to 6 months for at least the first 2 years, then every 6 months for another 3 years.

• After 5 years, chest radiographs are performed at regular intervals between 6 and 12 months

Role of PET• For small nodules (i.e.

10 mm) the sensitivity 20- 30 %;

• Nodules larger than 10 mm the sensitivity 80 - 90%.

Transthoracic needle aspiration biopsy (TNAB) - the initial procedure for the diagnosis of pulmonary nodules.• Sensitivity for malignant lesions - 86.1% (range, 83.8-

88.4%), with a pooled specificity - 98.8% (range, 98.4-99.2%)

Bronchoscopy with transbronchial needle aspiration (TBNA)• Diagnostic yield for lesions less than 2cm in diameter

is 54%, compared with 80% for those more than 3cm in diameter.

• For lesions located in the lower lobe basilar segments or in the apical segments of the upper lobes, yield is 58%, compared with 83% for other locations, and

• For lesions with sharp borders, the yield is 54%, compared with 83% for lesions with fuzzy borders.

Surgery • In 1882, Weinlechener performed the first operation to

remove two pulmonary metastases (en bloc chest wall resection) in a patient with sarcoma who subsequently died 1 day later.

• Kronlein successfully resected a chest wall sarcoma and its pulmonary metastasis in 1883.

• After 7 years, the patient died with recurrent disease.

Surgical indications • No other known extrapulmonary metastases - If additional

metastases are present, they should be considered amenable to surgical or some other form of therapy

• Good surgical candidates from the standpoint of cardiopulmonary and other comorbid conditions

• The location of the metastatic lesion is such that it can be completely resected with reasonable (depending on baseline pulmonary status) preservation of the remaining normal lung

• The primary tumor site has been controlled or resected

Surgery • Goal - complete resection of the lesion with maximal

preservation of normal parenchyma

• Bilateral disease

Staged thoracotomy

Clamshell

hemiclamshell

• Formal node dissection not indicated

• Wedge resection is enough

histology Without surgery With surgery

all 25- 40%

STS 20-40%

osteosarcoma 0-17% 20-40%

Breast ca 11% 35-50%

melanoma 3-4% 21-36%

colorectal <5% 40-45%

Renal cell ca 13-54%

VATSAdvantages of minimally invasive procedure

INDICATIONS

1. U/L disease 2. Fewer lesions (3-4)3. < 3cm in size 4. Peripherally located

Prognostic factorsStudy Tumor

Subgroup(s) with Improved Survival DFI (Y) Resectability (Yes/No)

Resected Nodules (n)

Pastorino et al.22

All Germ cell 3 Yes 1 vs. >1

Billingsley et al.23

STS Gynecologic sarcoma 1 Yes No

Pfannschmidt et al.61

Renal cell Node negative 2 Yes 7 vs. >7

Saito et al.94 Colon CEA <10 ng/mL, node negative

NS NS 1 vs. >1

Saeter et al.45 Osteosarcoma Response to chemotherapy NS Yes 1 vs. >1

Seki et al.64 Uterine cervix Tumor <3 cm NS Yes NS

Liu et al.62 Head and neck

Glandular tumors 2 Yes NS

Friedel et al.59 Breast   3 Yes NS

CEA, carcinoembryonic antigen; DFI, disease-free interval; NS, not stated; STS, soft tissue sarcoma.

Individual malignancies

Sarcomas• 80-90% metastasis is to lungs• 25% will develop mets majority within 2 years • 40-60 % in case of high grade tumors• Half of the patients relapse after R0 resection• Highest predisposition with LMS,MFH,synovial sarcoma • 5 yr survival – 35-40%• Poor Prognostic indicators

o Three or more lesions o Largest lesion with diameter >2 cmo High grade primary tumor

Colonmetastatic

• Typically involves regional lymph nodes, liver, and lung

• 8.7% develops lung metastasis, and only around 1% are candidates for metastasectomy

• Lung metastasis - significantly higher (11.5%) after resection of rectal carcinoma than after resection of right (3.8%) or left (3.4%) colon carcinoma

• Only complete resection and low preoperative carcinoembryonic antigen level - statistically significant indicators of a good prognosis in multivariate analysis

• Synchronous liver and lung metastasis even if resectable - worse prognosis

• Patient who undergoes curative resection of liver metastasis, only to develop lung lesions later – 5 yr survival 20 – 30%

Breast• Occur through lymphatic channels via internal mammary or

mediastinal lymph nodes, or both

• Solitary lesions - fewer than 1% of all patients with metastatic breast cancer

• Solitary lung metastasis - survival rate of 44% at 5 years and 23% at 10 and 15 years

• The 5-year survival was 37% after the first procedure and remained as high as 40% at 5 years after repeated thoracotomies.

Head and Neck• Except for cancers of the lip, tonsil, and adenoid,

metastasize initially to the lung

• Difficulty is to differentiate between a metastatic lesion and a primary lung carcinoma

• Five year survival 30-60%

Melanoma• The resection of pulmonary metastasis , in general,

disappointing

• The 5-year survival in those with complete resection - 21%

• Four risk factors that adversely affect survival:o nodular histology, o two or more metastases, o a disease-free interval of 5 years or less, and o the presence of extrathoracic metastases

Germ Cell TumorsINDICATIONS FOR RESECTION • an absence of response to chemotherapy, • a partial response followed by recurrence while on

chemotherapy, • recurrence after standard and second-line chemotherapy, • to determine the presence of residual viable tumor, and • to resect enlarging benign teratomatous elements of the tumor

*necrosis in 54% of patients, mature teratoma in 33%, and residual cancer in 13%

Ewing's Sarcoma Family of Tumors - Surgical resection of pulmonary metastasis does not appear to improve survival and should be limited to patients with pulmonary relapse only• use - whole lung radiation, dose-intensified chemotherapy

Gynecologic Cancers - Isolated lung metastasis from uterine or cervical carcinoma is relatively rareChemotherapy is the primary treatment for metastatic choriocarcinomaResistant choriocarcinoma, surgical resection - 5-year survival rate of 50%

Bronchoscopic Intervention

• Nd:YAG laser resection of the endoluminal tumor• Electrocauterization• Argon plasma coagulation• Cryotherapy• Brachytherapy• Mechanical removal of the obstruction with rigid

bronchoscopy• Endoluminal stent placement

Radiofrequency Ablation• Maximum size – 3 cm• No of lesions – 4Mostly air filled pulmonary parenchyma acts as a thermal insulatorComplications – pneumothorax (25% require ICD)Pleurisy, hemorrhage, infection

SBRTHigh doses can be delivered – upto 20 GyHilar and central mediastinal tumors – relative CIMajor toxicity around 10%

1. Surgical resection of pulmonary metastases is safe and

effective

2. VATS is an acceptable alternative that is both safe and

efficacious in properly selected cases

3. 25% of cases more metastases found at the time of surgery

than detected by pre op scans

Thank you