This calculator provides an ESTIMATE of life expectancy for individuals diagnosed with prostate cancer. It is crucial to understand that this tool is for informational purposes only and does not substitute professional medical advice. Life expectancy is influenced by a complex interplay of factors, including the specific characteristics of the cancer, the patient's overall health, age, and the effectiveness of treatment.
Factors Considered:
Current Age: Age at diagnosis and current age are fundamental to life expectancy calculations.
Gleason Score: This score (ranging from 2 to 10) reflects how aggressive the cancer cells appear under a microscope. Higher scores (e.g., 7 and above) indicate more aggressive cancer, potentially impacting life expectancy.
Cancer Stage: The stage describes how far the cancer has spread. Early-stage cancers (Stage I & II) are typically confined to the prostate, while later stages (Stage III & IV) involve spread to nearby tissues or distant organs, significantly affecting prognosis.
PSA Level: Prostate-Specific Antigen (PSA) is a protein produced by prostate cells. Elevated levels can indicate cancer, and very high levels, especially when combined with other risk factors, may suggest a more advanced or aggressive disease.
Treatment Status: Whether the cancer is untreated, undergoing treatment, or has been treated can influence the long-term outlook. Effective treatment can significantly improve survival rates.
How the Calculation Works (Simplified Model):
This calculator uses a simplified actuarial approach based on generalized survival data for prostate cancer patients. It combines the input factors to provide a statistical estimate.
The core logic involves:
Establishing a baseline life expectancy for the given age using general population data.
Adjusting this baseline based on the severity of the prostate cancer (Gleason Score, Stage, PSA Level). Higher risk factors generally lead to a reduction in estimated life expectancy.
Further adjusting for treatment status. Patients who have undergone successful treatment for localized or early-stage cancer generally have a better prognosis than those with untreated or metastatic disease.
Specific statistical models, such as those used by SEER (Surveillance, Epidemiology, and End Results) or other cancer registries, often employ multivariate analysis considering many more detailed parameters than what is captured in this simplified calculator. The output here is a broad estimation.
Important Considerations:
Individual Variation: Every patient is unique. Factors not included here, such as co-existing health conditions (diabetes, heart disease), lifestyle, response to treatment, and genetic predispositions, play a vital role.
Advancements in Treatment: Medical science is constantly evolving. New treatments and therapies can significantly alter prognoses over time.
Active Surveillance: For some low-risk prostate cancers, active surveillance is a management strategy. This calculator assumes a more active disease state or post-treatment status depending on the selected option.
Always consult with your oncologist and healthcare team for personalized information about your prognosis and treatment plan. This calculator is not a diagnostic tool.
function calculateLifeExpectancy() {
var age = parseFloat(document.getElementById("age").value);
var gleasonScore = parseInt(document.getElementById("gleasonScore").value);
var stage = parseInt(document.getElementById("stage").value);
var psaLevel = parseFloat(document.getElementById("psaLevel").value);
var treatmentStatus = document.getElementById("treatmentStatus").value;
var resultDiv = document.getElementById("result");
resultDiv.innerHTML = "; // Clear previous result
// — Input Validation —
if (isNaN(age) || age <= 0) {
resultDiv.innerHTML = "Please enter a valid current age.";
return;
}
if (isNaN(psaLevel) || psaLevel = 8) {
riskModifier *= 0.75; // Significantly reduces expectancy for high grade
} else if (gleasonScore === 7) {
riskModifier *= 0.90; // Moderately reduces expectancy for intermediate grade
} else if (gleasonScore === 6) {
riskModifier *= 0.98; // Small reduction for low grade
}
// Adjust for Stage
if (stage === 4) {
riskModifier *= 0.50; // Significantly reduces expectancy for metastatic
} else if (stage === 3) {
riskModifier *= 0.80; // Reduces expectancy for locally advanced
} else if (stage === 2) {
riskModifier *= 0.95; // Small reduction for localized stage II
} else if (stage === 1) {
riskModifier *= 0.99; // Minimal reduction for localized stage I
}
// Adjust for PSA Level
if (psaLevel > 20) {
riskModifier *= 0.70;
} else if (psaLevel > 10) {
riskModifier *= 0.85;
} else if (psaLevel > 4) {
riskModifier *= 0.95;
}
// Adjust for Treatment Status
if (treatmentStatus === "untreated" && stage > 1) { // Assume untreated and not stage I is higher risk
riskModifier *= 0.85;
} else if (treatmentStatus === "treated") {
// Successful treatment might improve prognosis, but data is complex.
// For simplicity, let's assume treated status doesn't drastically reduce expectancy compared to untreated/advanced cases IF other factors are managed.
// However, if cancer has returned or spread post-treatment, it's different.
// Let's apply a slight negative modifier here for simplicity as it suggests the cancer was significant enough to require treatment.
riskModifier *= 0.97;
}
var adjustedRemainingLifeExpectancy = remainingLifeExpectancy * riskModifier;
// Ensure the result is not negative and has a reasonable lower bound
adjustedRemainingLifeExpectancy = Math.max(0, adjustedRemainingLifeExpectancy);
// Set a minimum remaining expectancy, e.g., 1 year, as it's unlikely to be zero unless death is imminent.
adjustedRemainingLifeExpectancy = Math.max(1, adjustedRemainingLifeExpectancy);
var estimatedLifeExpectancy = age + adjustedRemainingLifeExpectancy;
// Display the result
resultDiv.innerHTML = "Estimated Remaining Life Years: " + Math.round(adjustedRemainingLifeExpectancy) + " years";
resultDiv.innerHTML += "Estimated Total Lifespan: " + Math.round(estimatedLifeExpectancy) + " years";
}