Chemotherapy for lung cancer: approaches

Chemotherapy remains the mainstay of treatment for two large groups of cancers: small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC), unless the tumor has driver mutations or if targeted/immunotherapy is unavailable or insufficient. Even in the era of targeted and immune drugs, the platinum "double" remains a workhorse, enhancing the effectiveness of radiation therapy, reducing tumor mass before surgery, and reducing the risk of recurrence after radical treatment. Current guidelines explicitly list the platinum combination as the standard in these scenarios. [1]

For SCLC, chemotherapy is initiated quickly, often without delay until after radiation therapy, as this tumor grows rapidly and responds best to systemic therapy in the first few weeks. In limited-stage disease, it is combined with radiation therapy; in advanced disease, immunotherapy (such as atezolizumab or durvalumab) is added to platinum and etoposide: this increases overall survival compared to chemotherapy alone. [2]

In NSCLC, indications depend on the "biology" and stage. In early stages, postoperative adjuvant cisplatin-containing regimens provide a survival benefit of approximately 5% after 5 years (the effect is greatest in stages II-III). In locally advanced stages, chemotherapy is combined with radiation therapy (competitively), and in metastatic disease, platinum-based therapies remain the standard in the absence of activating mutations or in combination with immunotherapy. [3]

If driver mutations (e.g., EGFR, ALK) are detected in NSCLC, inhibitors of these targets are often the first-line treatment, with chemotherapy being introduced later if sensitivity is lost. However, even in these cases, platinum combinations remain an important second-line option or component of combination therapy. [4]

What regimens are used for NSCLC: by histology and treatment objective

In NSCLC, the choice of the "platinum dual" depends on the histological type. For non-squamous cell cancer (adenocarcinoma, etc.), the standard is cisplatin + pemetrexed; for squamous cell cancer, cisplatin + gemcitabine, and carboplatin + paclitaxel (or docetaxel/nab-paclitaxel) are also possible, depending on the clinical situation. Historically, it was the comparison of cisplatin/pemetrexed versus cisplatin/gemcitabine that demonstrated superior tolerability and survival benefits in adenocarcinomas. [5]

In the adjuvant setting after surgery (stages II-III), cisplatin-based regimens (often with vinorelbine, pemetrexed for non-squamous cell carcinoma) are preferred, with four cycles spaced 21 days apart. The cumulative effect, according to LACE data, is approximately +5% to 5-year survival; patients with higher stages benefit the most. Furthermore, according to modern protocols, maintenance immunotherapy is added in certain subgroups with positive PD-L1. [6]

In locally advanced stage (III), two strategies are possible: concurrent chemoradiation therapy with cisplatin/etoposide or carboplatin/paclitaxel, followed by maintenance durvalumab in the absence of progression. The choice of the platinum-second agent pair is dictated by comorbidities, renal function, and organ-preservation goals. [7]

In metastatic NSCLC without driver agents, platinum plus pemetrexed/paclitaxel/gemcitabine is often combined with immunotherapy (PD-1/PD-L1 inhibitors) – this has increased response rates and duration of disease control. In cases of significant comorbidity, carboplatin can be used as a substitute for cisplatin, with a slight loss of efficacy but better tolerability in fragile patients. [8]

Table 1. Common platinum "twos" for NSCLC (landmarks)

Situation	Preferred pairs
Non-squamous cell NSCLC (first line)	Cisplatin + pemetrexed; alternative: carboplatin + pemetrexed
Squamous cell NSCLC	Cisplatin + gemcitabine; alternative: carboplatin + paclitaxel/nab-paclitaxel
Chemoradiation stage III	Cisplatin + etoposide or carboplatin + paclitaxel
Adjuvant after surgery	Cisplatin + vinorelbine/pemetrexed (according to histology)

SCLC: Why Platinum + Etoposide, and Where Does Immunotherapy Place?

For SCLC, the historical and current standard remains platinum (cisplatin or carboplatin) plus etoposide. In limited-stage disease, this "twosome" is administered concurrently with radiation therapy, increasing the chance of long-term local control. In advanced-stage disease, immunotherapy (atezolizumab or durvalumab) is added to platinum and etoposide from the first cycles, which statistically prolongs survival compared to chemotherapy alone. [9]

The choice between cisplatin and carboplatin in SCLC depends on renal function, comorbidities, and tolerability: meta-analyses show similar efficacy but different toxicity profiles. In patients with fragile status or impaired renal function, carboplatin is generally preferred. [10]

In both limited and widespread disease, the number of cycles is often limited to 4-6, as further increments rarely add benefit and increase toxicity. After a response in widespread disease, maintenance immunotherapy with the same drug (if used in induction) is possible. [11]

Table 2. MRL: basic schemes

Stage	Induction circuit	Further
Limited	Cisplatin/carboplatin + etoposide + competitive RT	Control; selected individuals receive prophylactic brain irradiation
Common	Platinum + etoposide + atezolizumab/durvalumab (usually 4 cycles)	Maintenance immunotherapy

How the course works: cycles, examinations, response criteria

The classic platinum "double" cycle lasts 21 days: "Day 1" consists of platinum and the second drug (or platinum alone, if the second drug is administered on other days), followed by a recovery break. On average, 4-6 cycles are prescribed; more are only prescribed based on individual indications. Before each cycle, blood tests, creatinine (clearance), and electrolytes are checked, a physical examination is performed, and symptoms are assessed. [12]

Before the first line of metastatic treatment, baseline imaging (CT of the chest and abdomen ± MRI/PET as indicated) is performed. Response is reassessed, usually every 2 cycles according to RECIST: partial response, stabilization, or progression are recorded. The decision to continue/change is made at a consultation, taking into account the clinical presentation, imaging, and tolerability. [13]

In the adjuvant (post-operative) setting, monitoring is simpler: visits before each cycle, followed by a follow-up plan with periodic CT/X-ray checks, depending on the stage and national guidelines. The chemoradiation option adds dosimetric and clinical monitoring of radiation therapy, nutritional adjustments, and esophagitis prevention. [14]

Table 3. Approximate "rhythm" of the course

Stage	What's happening
Before the start	Laboratory, renal function assessment, imaging
Every cycle, day 1	Infusion of drugs, antiemetic prophylaxis, instructions
Between cycles	Self-monitoring, calling in case of red flags, taking supportive measures
Every 2 cycles	CT/MRI to assess response, plan revision

Side effects and how to prevent them

Side effects depend on the specific combination. Cisplatin is associated with high-risk nausea/vomiting, nephrotoxicity, and ototoxicity; prophylaxis includes highly effective antiemetic regimens (neurokinin-1 receptor antagonist + ondansetron/palonosetron + dexamethasone) and ample hydration with electrolyte monitoring. Carboplatin is less likely to cause nephrotoxicity and ototoxicity, but more likely to cause thrombocytopenia. [15]

Pemetrexed requires concomitant administration: folic acid, vitamin B12, and prophylactic dexamethasone premedication reduce hematological and cutaneous toxicity. Taxanes are associated with peripheral neuropathy, a risk that is reduced by adjusting the dose and infusion rate; if symptoms are severe, the regimen is modified. Gemcitabine is more likely to cause neutropenia and fatigue, and sometimes a "flu syndrome." [16]

In SCLC, myelosuppression and nausea/vomiting remain key. Colony-stimulating factors are indicated in patients with a high risk of febrile neutropenia. Combination regimens with immunotherapy add rare but fundamentally different toxicities (immune-mediated pneumonitis, colitis), requiring steroids and interruption of therapy. [17]

Table 4. Toxicity profiles (very brief)

Preparation	"Typical" risks	What to do in advance
Cisplatin	Nausea/vomiting (high risk), nephro-/ototoxicity	NK1+5-HT3+Dex; hydration; creatinine/magnesium control
Carboplatin	Thrombocytopenia	AUC selection; blood monitoring
Pemetrexed	Myelosuppression, rash	Folic acid + B12; dexamethasone
Taxanes	Neuropathy	Symptom control, dose adjustment
Etoposide	Neutropenia	Prevention of FN by risk

Special situations: old age, chronic renal failure, concomitant diseases

Old age per se is not a contraindication to platinum regimens: biological age and functional status are more important. In frail patients, carboplatin is often chosen over cisplatin, and doses are carefully calculated based on creatinine clearance (Cockcroft-Gault/Calvert formulas for AUC). In patients with underlying neuropathy, taxanes should be avoided or their doses reduced. [18]

In chronic kidney disease, cisplatin is limited; carboplatin is permitted in cases of moderate renal impairment with careful monitoring. In cases of significant cardiac risk, regimens with potential cardiotoxicity are avoided, and in chronic obstructive pulmonary disease, respiratory support and infection prevention are planned in advance. [19]

If driver mutations are identified, chemotherapy doesn't disappear from the arsenal; its role shifts to later lines or in combination. For EGFR-positive NSCLC, first-line therapy is osimertinib, but if progression occurs, the "platinum-double" regimen remains effective. For ALK/ROS1, the approach is similar: first, tyrosine kinase inhibitors, then chemotherapy. [20]

Efficacy: What to Expect in Response and Survival Rates

In adjuvant NSCLC, a 5-year survival benefit of approximately 5% has been confirmed in pooled analyses: this is small at the individual level, but significant across the population. In locally advanced disease, concurrent chemoradiation improves local control, and maintenance durvalumab after chemoradiation improves relapse-free survival in a significant proportion of patients. [21]

In metastatic NSCLC, platinum-based therapies produce objective responses in 20-40% of patients on average; the addition of immunotherapy increases both the response rate and the duration of responses in selected patients. In SCLC, responses to platinum plus etoposide are often high but tend to be short-lived; the addition of immunotherapy improves median survival. [22]

It's important to understand that chemotherapy is a tool in the toolbox: its power is maximized when combined with appropriate localized strategies (surgery/radiation therapy), timely immunotherapy, and high-quality supportive care. Personalization (by histology, mutations, PD-L1, and status) today determines the real benefit in each individual case. [23]

Table 5. Where the benefits are proven particularly strongly

Scenario	Result
Adjuvant "cisplatin +..." after removal of NSCLC II-III	≈ +5% to 5-year survival
Stage III NSCLC, chemoradiation → durvalumab	Longer without progression
Advanced SCLC: Platinum + Etoposide + IO	Higher overall survival rate
Metastatic NSCLC without drivers: platinum + IO	Higher frequency and duration of responses

Frequently Asked Questions (short FAQ)

Cisplatin or carboplatin – which is better?
Cisplatin is slightly more effective in some situations, but is more toxic to the kidneys and ears; carboplatin is better tolerated and more convenient for patients with comorbidities. The choice is individual. [24]

Is chemotherapy always necessary when immunotherapy is available?
Often, yes: platinum-immune combinations in metastatic NSCLC and platinum-etoposide-immune combinations in SCLC have yielded better results than monotherapy. The exception is tumors with driver mutations, where targeted therapy is used. [25]

How long does the course last?
Typically 4-6 cycles of 21 days each; longer cycles are rare and for special indications. In some regimens, maintenance immunotherapy or maintenance pemetrexed (for non-squamous cell NSCLC) follows. [26]

What tests and examinations are needed during treatment?
Before each cycle – general and biochemical analysis, creatinine, electrolytes; if indicated – audiometry during cisplatin. Imaging to assess response – usually every 2 cycles. [27]

Dose approaches (for discussion with a doctor)

Table 6. Typical intervals and “anchor” elements of the schemes

Scheme	Interval	Security anchor
Cisplatin + pemetrexed	q21d ×4-6	Folic acid, B12, dexamethasone; hydration
Cisplatin + gemcitabine	q21d ×4-6	Blood tests (neutropenia), liver enzymes
Carboplatin + paclitaxel	q21d ×4-6	Premedication for hypersensitivity, control of neuropathy
Platinum + etoposide (MRL)	q21d ×4-6	Prevention of FN at risk, antiemetics